Publications T. Helgaker



Publication list

1977
1980 1981 1982 1984 1986 1987 1988 1989
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
2010 2011 2012 2013 2014 2015 2016
    1977

  1. Leo Tolstoj: Om vold og kjærlighet (Zakon nasilija i zakon ljubvi),
    T. U. Helgaker,
    translation from Russian with introduction, Solum, Oslo 1977,
    ISBN 8256000740

  2. Boris Pilnjak: Armesjefens død (Povest’ nepogasjennoj luny),
    T. U. Helgaker,
    translation from Russian, in Moderne russiske fortellere, ed. G. Kjetsaa (Aschehoug, Oslo 1977), pp. 84–119,
    ISBN 8203088503

    1980

  3. Strukturundersøkelser av enkle dialkylsinkforbindelser,
    T. U. Helgaker,
    cand. scient. thesis, (Department of Chemistry, University of Oslo, 1980)

    1981

  4. Basis set considerations for the calculation of gradients in the LCAO formalism,
    J. Almlöf and T. Helgaker,
    Chem. Phys. Lett. 83, 125–128 (1981)
    DOI: 10.1016/0009-2614(81)80303-X

    1982

  5. Simple derivation of the potential energy gradient for an arbitrary electronic wave function,
    T. U. Helgaker,
    Int. J. Quantum Chem. 21, 939–940 (1982)
    DOI: 10.1002/qua.560210520

  6. The molecular structures of dimethyl-, diethyl- and dipropylzinc determined by gas phase electron diffraction. Normal coordinate analysis and ab initio molecular orbital calculations on dimethylzinc,
    A. Almenningen, T. U. Helgaker, A. Haaland, and S. Samdal,
    Acta Chem. Scand. A36, 159–166 (1982)
    DOI: 10.3891/acta.chem.scand.36a-0159

    1984

  7. A second-quantization approach to the analytical evaluation of response properties for perturbation-dependent basis sets,
    T. U. Helgaker and J. Almlöf,
    Int. J. Quantum Chem. 26, 275–291 (1984)
    DOI: 10.1002/qua.560260211

  8. Higher molecular-deformation derivatives of the configuration-interaction energy,
    J. Simons, P. Jørgensen, and T. U. Helgaker,
    Chem. Phys. 86, 413–432 (1984)
    DOI: 10.1016/0301-0104(84)80029-4

    1986

  9. Hamiltonian expansion in geometrical distortions,
    T. U. Helgaker,
    in Geometrical Derivatives of Energy Surfaces and Molecular Properties,
    P. Jørgensen and J. Simons, eds. (Reidel, Dordrecht, 1986), pp. 1–16
    DOI: 10.1007/978-94-009-4584-5_1

  10. Calculation of dipole moments, polarizabilities and their geometrical derivatives,
    T. U. Helgaker,
    in Geometrical Derivatives of Energy Surfaces and Molecular Properties,
    P. Jørgensen and J. Simons, eds. (Reidel, Dordrecht, 1986), pp. 115–133
    DOI: 10.1007/978-94-009-4584-5_9

  11. Walking on MCSCF potential energy surfaces: application to H2O2 and NH3,
    D. L. Yeager, H. J. Aa. Jensen, P. Jørgensen, and T. U. Helgaker,
    in Geometrical Derivatives of Energy Surfaces and Molecular Properties,
    P. Jørgensen and J. Simons, eds. (Reidel, Dordrecht, 1986), pp. 229–241
    DOI: 10.1007/978-94-009-4584-5_18

  12. Molecular Hessians for large-scale MCSCF wave functions,
    T. U. Helgaker, J. Almlöf, H. J. Aa. Jensen, and P. Jørgensen,
    J. Chem. Phys. 84, 6266–6279 (1986)
    DOI: 10.1063/1.450771

  13. Analytical calculation of MCSCF dipole-moment derivatives,
    T. U. Helgaker, H. J. Aa. Jensen, and P. Jørgensen,
    J. Chem. Phys. 84, 6280–6284 (1986)
    DOI: 10.1063/1.450772

  14. Systematic determination of MCSCF equilibrium and transition structures and reaction paths,
    H. J. Aa. Jensen, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 85, 3917–3929 (1986)
    DOI: 10.1063/1.450914

  15. Development of quantum chemical methods for analytical calculation of molecular properties,
    T. U. Helgaker,
    dr. philos. thesis, (Department of Chemistry, University of Oslo, 1986)

    1987

  16. The ground-state potential energy surface of diazene,
    H. J. Aa. Jensen, P. Jørgensen, and T. Helgaker,
    J. Am. Chem. Soc. 109, 2895–2901 (1987)
    DOI: 10.1021/ja00244a007

    1988

  17. A gradient extremal walking algorithm,
    P. Jørgensen, H. J. Aa. Jensen, and T. Helgaker,
    Theor. Chim. Acta 73, 55–65 (1988)
    DOI: 10.1007/BF00526650

  18. Effect of the crystalline environment on molecular geometries – an ab initio study of cyanamide,
    T. U. Helgaker and B. Klewe,
    Acta Chem. Scand. A42, 269–272 (1988)
    DOI: 10.3891/acta.chem.scand.42a-0269

  19. Gaussian basis sets for high-quality ab initio calculations,
    J. Almlöf, T. Helgaker, and P. R. Taylor,
    J. Phys. Chem. 92, 3029–3033 (1988)
    DOI: 10.1021/j100322a003

  20. Analytical calculation of geometrical derivatives in molecular electronic structure theory,
    T. Helgaker and P. Jørgensen,
    Adv. Quantum Chem. 19, 183–245 (1988)
    DOI: 10.1016/S0065-3276(08)60616-4

  21. Møller–Plesset energy derivatives,
    P. Jørgensen and T. Helgaker,
    J. Chem. Phys. 89, 1560–1570 (1988)
    DOI: 10.1063/1.455152

  22. Translational and rotational symmetries of molecular geometrical derivatives,
    T. Helgaker,
    Acta Chem. Scand. A42, 515–518 (1988)
    DOI: 10.3891/acta.chem.scand.42a-0515

  23. A multiconfigurational self-consistent reaction-field method,
    K. V. Mikkelsen, H. Ågren, H. J. Aa. Jensen, and T. Helgaker,
    J. Chem. Phys. 89, 3086–3095 (1988)
    DOI: 10.1063/1.454965

  24. Molecular wave functions and properties calculated using floating Gaussian orbitals,
    T. Helgaker and J. Almlöf,
    J. Chem. Phys. 89, 4889–4902 (1988)
    DOI: 10.1063/1.455659

    1989

  25. Configuration-interaction energy derivatives in a fully variational formulation,
    T. Helgaker and P. Jørgensen,
    Theor. Chim. Acta 75, 111–127 (1989)
    DOI: 10.1007/BF00527713

  26. Accurate calculations of the dynamic dipole polarizability of N2. A multiconfigurational linear response study using restricted active space (RAS) wavefunctions,
    H. J. Aa. Jensen, P. Jørgensen, T. Helgaker, and J. Olsen,
    Chem. Phys. Lett. 162, 355–360 (1989)
    DOI: 10.1016/0009-2614(89)87058-7

  27. A numerically stable procedure for calculating Møller–Plesset energy derivatives, derived using the theory of Lagrangians,
    T. Helgaker, P. Jørgensen, and N. C. Handy,
    Theor. Chim. Acta 76, 227–245 (1989)
    DOI: 10.1007/BF00532006

  28. Applications of second order MCSCF on electronic structures, reactions and spectra of molecules,
    H. Ågren, H. J. Aa. Jensen, T. Helgaker, P. Jørgensen, and J. Olsen,
    Annales de la Société Scientifique de Bruxelles 103, 149–181 (1989)

    1990

  29. Coupled cluster energy derivatives. Analytic Hessian for the closed-shell coupled cluster singles and doubles wave function: Theory and applications,
    H. Koch, H. J. Aa. Jensen, P. Jørgensen, T. Helgaker, G. E. Scuseria, and H. F. Schaefer III,
    J. Chem. Phys. 92, 4924–4940 (1990)
    DOI: 10.1063/1.457710

  30. Excitation energies from the coupled cluster singles and doubles linear response function (CCSDLR). Applications to Be, CH+, CO, and H2O,
    H. Koch, H. J. Aa. Jensen, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 93, 3345–3350 (1990)
    DOI: 10.1063/1.458815

  31. Integration of the classical equations of motion on ab initio molecular potential energy surfaces using gradients and Hessians: application to translational energy release upon fragmentation,
    T. Helgaker, E. Uggerud, and H. J. Aa. Jensen,
    Chem. Phys. Lett. 173, 145–150 (1990)
    DOI: 10.1016/0009-2614(90)80068-O

    1991

  32. Transition-state optimizations by trust-region image minimization,
    T. Helgaker,
    Chem. Phys. Lett. 182, 503–510 (1991)
    DOI: 10.1016/0009-2614(91)90115-P

  33. An electronic Hamiltonian for origin independent calculations of magnetic properties,
    T. Helgaker and P. Jørgensen,
    J. Chem. Phys. 95, 2595–2601 (1991)
    DOI: 10.1063/1.460912

  34. Excited state structures and vibronic spectra of H2CO+, HDCO+, and D2CO+ using molecular gradient and Hessian techniques,
    A. Cesar, H. Ågren, T. Helgaker, P. Jørgensen, and H. J. Aa. Jensen,
    J. Chem. Phys. 95, 5906–5917 (1991)
    DOI: 10.1063/1.461612

  35. An ab initio investigation of the potential energy function and rotation–vibration energies of H2O·Na+,
    V. Špirko, N. M. Daadoch, H. J. Aa. Jensen, P. Jørgensen, and T. Helgaker,
    Chem. Phys. Lett. 185, 265–269 (1991)
    DOI: 10.1016/S0009-2614(91)85058-5

    1992

  36. Spin–orbit coupling constants in a multiconfiguration linear response approach,
    O. Vahtras, H. Ågren, P. Jørgensen, H. J. Aa. Jensen, T. Helgaker, and J. Olsen,
    J. Chem. Phys. 96, 2118–2126 (1992)
    DOI: 10.1063/1.462063

  37. The second-order energy contribution from the spin–orbit interaction operator to the potential energy curve of Cr2,
    O. Vahtras, H. Ågren, P. Jørgensen, H. J. Aa. Jensen, and T. Helgaker,
    Intern. J. Quantum Chem. 41, 729–731 (1992)
    DOI: 10.1002/qua.560410509

  38. Indirect nuclear spin–spin coupling constants from multiconfiguration linear response theory,
    O. Vahtras, H. Ågren, P. Jørgensen, H. J. Aa. Jensen, S. B. Padkjær, and T. Helgaker,
    J. Chem. Phys. 96, 6120–6125 (1992)
    DOI: 10.1063/1.462654

  39. The magnetic hyperpolarizability anisotropy of the neon atom,
    M. Jaszuński, H. J. Aa. Jensen, P. Jørgensen, A. Rizzo, T. Helgaker, and K. Ruud,
    Chem. Phys. Lett. 191, 599–602 (1992)
    DOI: 10.1016/0009-2614(92)85595-2

  40. Dynamics of the reaction CH2OH+ → CHO+ + H2. Translational energy release from ab initio trajectory calculations,
    E. Uggerud and T. Helgaker,
    J. Am. Chem. Soc. 114, 4265–4268 (1992)
    DOI: 10.1021/ja00037a033

  41. Calculation of geometrical derivatives in molecular electronic structure theory,
    T. Helgaker and P. Jørgensen,
    in Methods in Computational Molecular Physics,
    S. Wilson and G. H. F. Diercksen, eds. (Plenum, New York, 1992), pp. 353–421

  42. Optimization of minima and saddle points,
    T. Helgaker,
    in Lecture Notes in Quantum Chemistry,
    B. Roos, ed. (Springer, Berlin, 1992), pp. 295–324
    DOI: 10.1007/978-3-642-58150-2_6

  43. Interconversion of diborane(4) isomers,
    J. F. Stanton, J. Gauss, R. J. Bartlett, T. Helgaker, P. Jørgensen, H. J. Aa. Jensen, and P. R. Taylor,
    J. Chem. Phys. 97, 1211–1216 (1992)
    DOI: 10.1063/1.463247

  44. On the evaluation of derivatives of Gaussian integrals,
    T. Helgaker and P. R. Taylor,
    Theor. Chim. Acta 83, 177–183 (1992)
    DOI: 10.1007/BF01132826

  45. Spin polarization in restricted electronic structure theory: Multiconfiguration self-consistent-field calculations of hyperfine coupling constants,
    B. Fernandez, P. Jørgensen, J. Byberg, J. Olsen, T. Helgaker, and H. J. Aa. Jensen,
    J. Chem. Phys. 97, 3412–3419 (1992)
    DOI: 10.1063/1.462977

  46. The hydrogen atom in crossed static electromagnetic and non-resonant laser fields,
    T. Helgaker and I. Tomashevsky,
    Phys. Scr. 46, 354–356 (1992)
    DOI: 10.1088/0031-8949/46/4/007

  47. First-order nonadiabatic coupling matrix elements from multiconfigurational self-consistent-field response theory,
    K. L. Bak, P. Jørgensen, H. J. Aa. Jensen, J. Olsen, and T. Helgaker,
    J. Chem. Phys. 97, 7573–7584 (1992)
    DOI: 10.1063/1.463477

  48. Multiconfigurational quadratic response functions for singlet and triplet perturbations: The phosphorescence lifetime of formaldehyde
    O. Vahtras, H. Ågren, P. Jørgensen, H. J. Aa. Jensen, T. Helgaker, and J. Olsen,
    J. Chem. Phys. 97, 9178–9187 (1992)
    DOI: 10.1063/1.463344

    1993

  49. Nuclear magnetic shielding tensor for the ethylenic carbon atom in tetrachlorocyclopropene,
    M. Jaszuński, K. L. Bak, P. Jørgensen, T. Helgaker, K. Ruud, and H. J. Aa. Jensen,
    Chem. Phys. Lett. 204, 608–610 (1993)
    DOI: 10.1016/0009-2614(93)89212-Z

  50. Direct atomic orbital based self-consistent-field calculations of nonlinear molecular properties. Application to the frequency dependent hyperpolarizability of para-nitroaniline,
    H. Ågren, O. Vahtras, H. Koch, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 98, 6417–6423 (1993)
    DOI: 10.1063/1.465099

  51. Large scale random phase calculations for direct self-consistent field wavefunctions,
    H. Koch, H. Ågren, P. Jørgensen, T. Helgaker, and H. J. Aa. Jensen,
    Chem. Phys. 172, 13–20 (1993)
    DOI: 10.1016/0301-0104(93)80102-F

  52. Frequency dependent hyperpolarizabilities of polyynes,
    M. Jaszuński, P. Jørgensen, H. Koch, H. Ågren, and T. Helgaker,
    J. Chem. Phys. 98, 7229–7235 (1993)
    DOI: 10.1063/1.464714

  53. Gauge-origin independent multiconfigurational self-consistent-field theory for vibrational circular dichroism,
    K. L. Bak, P. Jørgensen, T. Helgaker, K. Ruud, and H. J. Aa. Jensen,
    J. Chem. Phys. 98, 8873–8887 (1993)
    DOI: 10.1063/1.464445

  54. The nuclear spin–spin coupling in N2 and CO,
    O. Vahtras, H. Ågren, P. Jørgensen, T. Helgaker, and H. J. Aa. Jensen,
    Chem. Phys. Lett. 209, 201–206 (1993)
    DOI: 10.1016/0009-2614(93)80093-5

  55. Hartree–Fock limit magnetizabilities from London orbitals,
    K. Ruud, T. Helgaker, K. L. Bak, P. Jørgensen, and H. J. Aa. Jensen,
    J. Chem. Phys. 99, 3847–3859 (1993)
    DOI: 10.1063/1.466131

  56. Mechanism, energetics, kinetics and dynamics of the reaction C2H6+˙ → C2H4+˙ + H2,
    S. M. Bråten, T. Helgaker, E. Uggerud, and T. Vulpius,
    Org. Mass Spectrom. 28, 1262–1269 (1993)
    DOI: 10.1002/oms.1210281043

  57. Ab initio study of the NMR shielding constants and spin–spin coupling constants in cyclopropene,
    A. Barszczewicz, M. Jaszuński, K. Kamieńska-Trela, T. Helgaker, P. Jørgensen, and O. Vahtras,
    Theor. Chim. Acta 87, 19–28 (1993)
    DOI: 10.1007/BF01113526

    1994

  58. Frequency-dependent polarizabilities of O2 and van der Waals coefficients of dimers containing O2,
    H. Hettema, P. E. S. Wormer, P. Jørgensen, H. J. Aa. Jensen, and T. Helgaker,
    J. Chem. Phys. 100, 1297–1302 (1994)
    DOI: 10.1063/1.467256

  59. MCSCF calculations of nitrogen NMR shielding constants using London atomic orbitals,
    M. Jaszuński, T. Helgaker, K. Ruud, K. L. Bak, and P. Jørgensen,
    Chem. Phys. Lett. 220, 154–160 (1994)
    DOI: 10.1016/0009-2614(94)00163-4

  60. Basis set convergence of atomic axial tensors obtained from self-consistent field calculations using London atomic orbitals,
    K. L. Bak, P. Jørgensen, T. Helgaker, K. Ruud, and H. J. Aa. Jensen,
    J. Chem. Phys. 100, 6620–6627 (1994)
    DOI: 10.1063/1.467019

  61. MCSCF calculations of Verdet constants,
    M. Jaszuński, P. Jørgensen, A. Rizzo, K. Ruud, and T. Helgaker
    Chem. Phys. Lett. 222, 263–266 (1994)
    DOI: 10.1016/0009-2614(94)00350-5

  62. Multiconfigurational self-consistent field calculations of nuclear shieldings using London atomic orbitals,
    K. Ruud, T. Helgaker, R. Kobayashi, P. Jørgensen, K. L. Bak, and H. J. Aa. Jensen,
    J. Chem. Phys. 100, 8178–8185 (1994)
    DOI: 10.1063/1.466812

  63. Theoretical calculations of the magnetizability of some small fluorine-containing molecules using London atomic orbitals,
    K. Ruud, T. Helgaker, P. Jørgensen, and K. L. Bak,
    Chem. Phys. Lett. 223, 12–18 (1994)
    DOI: 10.1016/0009-2614(94)00407-2

  64. An ab initio nuclear magnetic resonance spectrum of vinyllithium,
    K. Ruud, T. Helgaker, P. Jørgensen, and K. L. Bak,
    Chem. Phys. Lett. 226, 1–10 (1994)
    DOI: 10.1016/0009-2614(94)00705-5

  65. A direct atomic orbital driven implementation of the coupled cluster singles and doubles (CCSD) model,
    H. Koch, O. Christiansen, R. Kobayashi, P. Jørgensen, and T. Helgaker,
    Chem. Phys. Lett. 228, 233–238 (1994)
    DOI: 10.1016/0009-2614(94)00898-1

  66. MCSCF reaction-path energetics and thermal rate-constants for the reaction of 3NH with H2,
    J. Ischtwan, P. Schwerdtfeger, S. D. Peyerimhoff, M. A. Collins, T. Helgaker, P. Jørgensen, and H. J. Aa. Jensen,
    Theor. Chim. Acta 89, 157–168 (1994)
    DOI: 10.1007/BF01132799

  67. Multiconfigurational self-consistent field calculations of nuclear magnetic resonance indirect spin–spin coupling constants,
    A. Barszczewicz, T. Helgaker, M. Jaszuński, P. Jørgensen, and K. Ruud,
    J. Chem. Phys. 101, 6822–6828 (1994)
    DOI: 10.1063/1.468310

  68. Magnetizability of hydrocarbons,
    K. Ruud, H. Skaane, T. Helgaker, K. L. Bak, and P. Jørgensen,
    J. Am. Chem. Soc. 116, 10135–10140 (1994)
    DOI: 10.1021/ja00101a036

  69. The Vegard–Kaplan band and the phosphorescent decay of N2,
    J. Olsen, B. Minaev, O. Vahtras, H. Ågren, P. Jørgensen, H. J. Aa. Jensen, and T. Helgaker,
    Chem. Phys. Lett. 231, 387–394 (1994)
    DOI: 10.1016/0009-2614(94)01300-4

  70. Basis set convergence and correlation effects in vibrational circular dichroism calculations using London atomic orbitals,
    K. L. Bak, P. Jørgensen, T. Helgaker, and K. Ruud,
    Faraday Discuss. 99, 121–129 (1994)
    DOI: 10.1039/fd9949900121

  71. Vibrational Raman optical activity calculations using London atomic orbitals,
    T. Helgaker, K. Ruud, K. L. Bak, P. Jørgensen, and J. Olsen,
    Faraday Discuss. 99, 165–180 (1994)
    DOI: 10.1039/fd9949900165

    1995

  72. Loss of H2 from CH3NH3+, CH3OH2+ and CH3FH+. Reaction mechanisms and dynamics from observation of metastable ion fragmentations and ab initio calculations,
    E. L. Øiestad, Å. M. L. Øiestad, H. Skaane, K. Ruud, T. Helgaker, E. Uggerud, and T. Vulpius,
    Eur. Mass Spectrom. 1, 121–129 (1995)
    DOI: 10.1255/ejms.145

  73. Orbital connections for perturbation-dependent basis sets,
    J. Olsen, K. L. Bak, K. Ruud, T. Helgaker, and P. Jørgensen,
    Theor. Chim. Acta 90, 421–439 (1995)
    DOI: 10.1007/BF01113545

  74. Ab initio calculation of electronic circular dichroism for trans-cyclooctene using London atomic orbitals,
    K. L. Bak, Aa. E. Hansen, K. Ruud, T. Helgaker, J. Olsen, and P. Jørgensen,
    Theor. Chim. Acta 90, 441–458 (1995)
    DOI: 10.1007/BF01113546

  75. A numerically stable orbital connection for the calculation of analytical Hessians using perturbation-dependent basis sets,
    K. Ruud, T. Helgaker, J. Olsen, P. Jørgensen, and K. L. Bak,
    Chem. Phys. Lett. 235, 47–52 (1995)
    DOI: 10.1016/0009-2614(95)00092-I

  76. Accurate magnetizabilities of the isoelectronic series BeH, BH, and CH+. The MCSCF–GIAO approach,
    K. Ruud, T. Helgaker, K. L. Bak, P. Jørgensen, and J. Olsen,
    Chem. Phys. 195, 157–169 (1995)
    DOI: 10.1016/0301-0104(95)00052-P

  77. NMR shielding tensors and indirect spin–spin coupling tensors in HCN, HNC, CH3CN, and CH3NC molecules,
    A. Barszczewicz, T. Helgaker, M. Jaszuński, P. Jørgensen, and K. Ruud,
    J. Magn. Reson. A 114, 212–218 (1995)
    DOI: 10.1006/jmra.1995.1128

  78. Random-phase calculations of frequency-dependent polarizabilities and hyperpolarizabilities of long polyene chains,
    Y. Luo, H. Ågren, H. Koch, P. Jørgensen, and T. Helgaker,
    Phys. Rev. B 51, 14949–14957 (1995)
    DOI: 10.1103/PhysRevB.51.14949

  79. Electric field dependence of magnetic properties: Multiconfigurational self-consistent field calculations of hypermagnetizabilities and nuclear shielding polarizabilities of N2, C2H2, HCN, and H2O,
    A. Rizzo, T. Helgaker, K. Ruud, A. Barszczewicz, M. Jaszuński, and P. Jørgensen,
    J. Chem. Phys. 102, 8953–8966 (1995)
    DOI: 10.1063/1.468949

  80. SCF calculations of the NMR shielding tensor for the ethylenic carbon atom in C3Cl4,
    M. Jaszuński, T. Helgaker, K. Ruud, P. Jørgensen, K. L. Bak, and H. Koch,
    Mol. Phys. 85, 671–673 (1995)
    DOI: 10.1080/00268979500101381

  81. NMR properties of N3. A comparison of theory and experiment,
    M. Jaszuński, S. Szymański, O. Christiansen, P. Jørgensen, T. Helgaker, and K. Ruud,
    Chem. Phys. Lett. 243, 144–150 (1995)
    DOI: 10.1016/0009-2614(95)00806-F

  82. Second-order methods for the optimization of molecular potential energy surfaces,
    T. Helgaker, K. Ruud, and P. R. Taylor,
    in The Reaction Path in Chemistry: Current Approaches and Perspectives,
    D. Heidrich, ed., (Kluwer, Dordrecht, 1995), pp. 109–136
    DOI: 10.1007/978-94-015-8539-2_6

  83. Gaussian basis sets and molecular integrals,
    T. Helgaker and P. R. Taylor,
    in Modern Electronic Structure Theory, Part II,
    D. R. Yarkony, ed., (World Scientific, Singapore, 1995), pp. 725–856
    DOI: 10.1142/9789812832115_0001

    1996

  84. Long-range effects of interatomic interactions on NMR shielding constants,
    A. Barszczewicz, M. Jaszuński, T. Helgaker, and K. Ruud,
    Chem. Phys. Lett. 250, 1–8 (1996)
    DOI: 10.1016/0009-2614(96)00005-X

  85. The integral-direct coupled cluster singles and doubles model,
    H. Koch, A. Sánchez de Merás, T. Helgaker, and O. Christiansen,
    J. Chem. Phys. 104, 4157–4165 (1996)
    DOI: 10.1063/1.471227

  86. Efficient parallel implementation of response theory: calculations of the second hyperpolarizability of polyacenes,
    P. Norman, D. Jonsson, H. Ågren, P. Dahle, K. Ruud, T. Helgaker, and H. Koch,
    Chem. Phys. Lett. 253, 1–7 (1996)
    DOI: 10.1016/0009-2614(96)00246-1

  87. Magnetizability and nuclear shielding constants of solvated water,
    K. V. Mikkelsen, K. Ruud, and T. Helgaker,
    Chem. Phys. Lett. 253, 443–447 (1996)
    DOI: 10.1016/0009-2614(96)00264-3

  88. The molecular structure of ferrocene,
    H. Koch, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 104, 9528–9530 (1996)
    DOI: 10.1063/1.471695

  89. MCSCF calculations of hypermagnetizabilities and nuclear shielding polarizabilities of CO and CH4,
    S. Coriani, A. Rizzo, K. Ruud, and T. Helgaker,
    Mol. Phys. 88, 931–947 (1996)
    DOI: 10.1080/00268979650025984

  90. Ab initio studies of the [AX]2 spin systems of cis- and trans-N2F2,
    M. Jaszuński, T. Helgaker, and K. Ruud,
    Magn. Reson. Chem. 34, 646–649 (1996)
    DOI: 10.1002/(SICI)1097-458X(199608)34:8<646::AID-OMR947>3.0.CO;2-5

  91. Perturbation-dependent atomic orbitals for the calculation of spin-rotation constants and rotational g tensors,
    J. Gauss, K. Ruud, and T. Helgaker,
    J. Chem. Phys. 105, 2804–2812 (1996)
    DOI: 10.1063/1.472143

  92. Energetics and dynamics of intermolecular proton-transfer processes. 2. Ab initio direct dynamics calculations of the reaction H3O+ + NH3 → NH4+ + H2O,
    H.-H. Bueker, T. Helgaker, K. Ruud, and E. Uggerud,
    J. Phys. Chem. 100, 15388–15392 (1996)
    DOI: 10.1021/jp960943b

  93. Large-scale calculations of excitation energies in coupled cluster theory: The singlet excited states of benzene,
    O. Christiansen, H. Koch, A. Halkier, P. Jørgensen, T. Helgaker, and A. Sánchez de Merás,
    J. Chem. Phys. 105, 6921–6939 (1996)
    DOI: 10.1063/1.471985

  94. Full CI calculations of the magnetizability and rotational g factor of the hydrogen molecule,
    K. Ruud, P.-O. Åstrand, T. Helgaker, and K. V. Mikkelsen,
    J. Mol. Struct.: THEOCHEM 388, 231–235 (1996)
    DOI: 10.1016/S0166-1280(96)80036-4

  95. Integral direct calculation of CC2 excitation energies: singlet excited states of benzene,
    O. Christiansen, H. Koch, P. Jørgensen, and T. Helgaker,
    Chem. Phys. Lett. 263, 530–539 (1996)
    DOI: 10.1016/S0009-2614(96)01245-6

  96. Magnetizabilities and nuclear shielding constants of the fluoromethanes in the gas phase and solution,
    P.-O. Åstrand, K. V. Mikkelsen, K. Ruud, and T. Helgaker,
    J. Phys. Chem. 100, 19771–19782 (1996)
    DOI: 10.1021/jp961701e

    1997

  97. The magnetizability, rotational g tensor, and quadrupole moment of PF3 revisited,
    K. Ruud and T. Helgaker,
    Chem. Phys. Lett. 264, 17–23 (1997)
    DOI: 10.1016/S0009-2614(96)01305-X

  98. A multipole reaction-field model for gauge-origin independent magnetic properties of solvated molecules,
    K. V. Mikkelsen, P. Jørgensen, K. Ruud, and T. Helgaker,
    J. Chem. Phys. 106, 1170–1180 (1997)
    DOI: 10.1063/1.473212

  99. The CC3 model: An iterative coupled cluster approach including connected triples,
    H. Koch, O. Christiansen, P. Jørgensen, A. M. Sánchez de Merás, and T. Helgaker,
    J. Chem. Phys. 106, 1808–1818 (1997)
    DOI: 10.1063/1.473322

  100. Cotton–Mouton effect and shielding polarizabilities in ethylene: an MCSCF study,
    S. Coriani, A. Rizzo, K. Ruud, and T. Helgaker,
    Chem. Phys. 216, 53–66 (1997)
    DOI: 10.1016/S0301-0104(97)00019-0

  101. Mechanisms, energetics and dynamics of a key reaction sequence during the decomposition of nitromethane: HNO + HNO → N2O + H2O,
    K. Ruud, T. Helgaker, and E. Uggerud,
    J. Mol. Struct.: THEOCHEM 393, 59–71 (1997)
    DOI: 10.1016/S0166-1280(96)04852-X

  102. The prediction of molecular equilibrium structures by the standard electronic wave functions,
    T. Helgaker, J. Gauss, P. Jørgensen, and J. Olsen,
    J. Chem. Phys. 106, 6430–6440 (1997)
    DOI: 10.1063/1.473634

  103. The magnetizability anisotropy and rotational g factor of deuterium hydride and the deuterium molecule,
    P.-O. Åstrand, K. Ruud, K. V. Mikkelsen, and T. Helgaker,
    Chem. Phys. Lett. 271, 163–166 (1997)
    DOI: 10.1016/S0009-2614(97)00429-6

  104. Ab initio calculation of the NMR shielding and indirect spin–spin coupling constants of fluoroethylene,
    T. Helgaker, M. Jaszuński, and K. Ruud,
    Mol. Phys. 91, 881–889 (1997)
    DOI: 10.1080/002689797170987

  105. Principles of direct 4-component relativistic SCF: application to caesium auride,
    T. Saue, K. Fægri, T. Helgaker, and O. Gropen,
    Mol. Phys. 91, 937–950 (1997)
    DOI: 10.1080/002689797171058

  106. Basis-set convergence of correlated calculations on water,
    T. Helgaker, W. Klopper, H. Koch, and J. Noga,
    J. Chem. Phys. 106, 9639–9646 (1997)
    DOI: 10.1063/1.473863

  107. First-order one-electron properties in the integral-direct coupled cluster singles and doubles model,
    A. Halkier, H. Koch, O. Christiansen, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 107, 849–866 (1997)
    DOI: 10.1063/1.474384

  108. The Cotton-Mouton effect of liquid water. Part I: The dielectric continuum model,
    K. Ruud, T. Helgaker, A. Rizzo, S. Coriani, and K. V. Mikkelsen,
    J. Chem. Phys. 107, 894–901 (1997)
    DOI: 10.1063/1.474387

  109. CCSDT calculations of molecular equilibrium geometries,
    A. Halkier, P. Jørgensen, J. Gauss, and T. Helgaker,
    Chem. Phys. Lett. 274, 235–241 (1997)
    DOI: 10.1016/S0009-2614(97)00652-0

  110. Electric and magnetic properties of the nitroethene molecule,
    P.-O. Åstrand, K. Ruud, K. V. Mikkelsen, and T. Helgaker,
    Mol. Phys. 92, 89–96 (1997)
    DOI: 10.1080/002689797170644

  111. A systematic ab initio study of the water dimer in hierarchies of basis sets and correlations models,
    A. Halkier, H. Koch, P. Jørgensen, O. Christiansen, I. M. Beck Nielsen, and T. Helgaker,
    Theor. Chem. Acc. 97, 150–157 (1997)
    DOI: 10.1007/s002140050248

  112. Multiple basis sets in calculations of triples corrections in coupled-cluster theory,
    W. Klopper, J. Noga, H. Koch, and T. Helgaker,
    Theor. Chem. Acc. 97, 164–176 (1997)
    DOI: 10.1007/s002140050250

  113. Extensive relativistic calculations on the palladium hydride molecule,
    M. Sjøvoll, H. Fagerli, O. Gropen, J. Almlöf, T. Saue, J. Olsen, and T. Helgaker,
    J. Chem. Phys. 107, 5496–5501 (1997)
    DOI: 10.1063/1.474254

  114. The effect of correlation on molecular magnetizabilities and rotational g tensors,
    K. Ruud, T. Helgaker, and P. Jørgensen,
    J. Chem. Phys. 107, 10599–10606 (1997)
    DOI: 10.1063/1.474174

    1998

  115. The Cotton–Mouton effect of liquid water. Part II: The semi-continuum model,
    K. Ruud, H. Ågren, P. Dahle, T. Helgaker, A. Rizzo, S. Coriani, H. Koch, K. O. Sylvester-Hvid, and K. V. Mikkelsen,
    J. Chem. Phys. 108, 599–603 (1998)
    DOI: 10.1063/1.475422

  116. Solvent effects on nuclear shieldings and spin–spin couplings of hydrogen selenide,
    P.-O. Åstrand, K. V. Mikkelsen, P. Jørgensen, K. Ruud, and T. Helgaker,
    J. Chem. Phys. 108, 2528–2537 (1998)
    DOI: 10.1063/1.475656

  117. Integral-direct coupled cluster calculations of frequency-dependent polarizabilities, transition probabilities and excited-state properties,
    O. Christiansen, A. Halkier, H. Koch, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 108, 2801–2816 (1998)
    DOI: 10.1063/1.475671

  118. The molecular Zeeman effect of nonbornadiene, its g-values, magnetizability anisotropies, and molecular electric quadrupole moment; a high-resolution microwave Fourier-transform study combined with quantum chemical calculations,
    K. Voges, D. H. Sutter, K. Ruud, and T. Helgaker,
    Z. Naturforsch. 53a, 67–76 (1998)
    DOI: 10.1515/zna-1998-1-211

  119. The Hartree–Fock limit magnetizability of C60,
    K. Ruud, H. Ågren, T. Helgaker, P. Dahle, H. Koch, and P. R. Taylor,
    Chem. Phys. Lett. 285, 205–209 (1998)
    DOI: 10.1016/S0009-2614(98)00042-6

  120. Spin–orbit and correlation effects in platinum hydride (PtH),
    M. Sjøvoll, H. Fagerli, O. Gropen, J. Almlöf, J. Olsen, and T. U. Helgaker,
    Int. J. Quantum Chem. 68, 53–64 (1998)
    DOI: 10.1002/(SICI)1097-461X(1998)68:1<53::AID-QUA2>3.0.CO;2-X

  121. Basis-set convergence in correlated calculations on Ne, N2, and H2O,
    A. Halkier, T. Helgaker, P. Jørgensen, W. Klopper, H. Koch, J. Olsen, and A. K. Wilson,
    Chem. Phys. Lett. 286, 243–252 (1998)
    DOI: 10.1016/S0009-2614(98)00111-0

  122. Generalized integral-screening for efficient calculations of nonlinear optical properties of large molecules,
    K. Ruud, D. Jonsson, P. Norman, H. Ågren, T. Saue, H. J. Aa. Jensen, P. Dahle, and T. Helgaker
    J. Chem. Phys. 108, 7973–7979 (1998)
    DOI: 10.1063/1.476237

  123. Basis-set dependence of nuclear spin-spin coupling constants,
    T. Helgaker, M. Jaszuński, K. Ruud, and A. Górska,
    Theor. Chem. Acc. 99, 175–182 (1998)
    DOI: 10.1007/s002140050321

  124. Extrapolation to the limit of a complete basis set for electronic structure calculations on the N2 molecule,
    W. Klopper and T. Helgaker,
    Theor. Chem. Acc. 99, 265–271 (1998)
    DOI: 10.1007/s002140050335

  125. Full CI calculations of magnetic properties of the H2 molecule in the B1Σu+ state,
    T. Helgaker, M. Jaszuński, and K. Ruud,
    Pol. J. Chem. 72, 1405–1410 (1998)

  126. Electric and magnetic properties of fullerenes,
    D. Jonsson, P. Norman, K. Ruud, H. Ågren, and T. Helgaker,
    J. Chem. Phys. 109, 572–577 (1998)
    DOI: 10.1063/1.476593

  127. Electric field gradient, generalized Sternheimer shieldings and electric field gradient polarizabilities by multiconfigurational SCF response,
    A. Rizzo, K. Ruud, T. Helgaker, and M. Jaszuński,
    J. Chem. Phys. 109, 2264–2274 (1998)
    DOI: 10.1063/1.476794

  128. Rovibrational effects, temperature dependence, and isotope effects on the nuclear shielding tensors of water: A new 17O absolute shielding scale,
    J. Vaara, J. Lounila, K. Ruud, and T. Helgaker
    J. Chem. Phys. 109, 8388–8397 (1998)
    DOI: 10.1063/1.477501

  129. Atomic charges of the water molecule and the water dimer,
    P.-O. Åstrand, K. Ruud, K. V. Mikkelsen, and T. Helgaker,
    J. Phys. Chem. A 102, 7686–7691 (1998)
    DOI: 10.1021/jp980574e

  130. Vibrationally averaged magnetizabilities and rotational g tensors of the water molecule,
    K. Ruud, J. Vaara, J. Lounila, and T. Helgaker,
    Chem. Phys. Lett. 297, 467–474 (1998)
    DOI: 10.1016/S0009-2614(98)01155-5

  131. Gradient Theory,
    T. Helgaker,
    in The Encyclopedia of Computational Chemistry,
    P. v. R. Schleyer, N. L. Allinger, T. Clark, J. Gasteiger, P. A. Kollman, H. F. Schaefer III, and P. R. Schreiner, eds. (Wiley, Chichester, 1998), pp. 1157–1169

    1999

  132. Ab initio methods for the calculation of NMR shielding and indirect spin–spin coupling constants,
    T. Helgaker, M. Jaszuński, and K. Ruud,
    Chem. Rev. 99, 293–352 (1999)
    DOI: 10.1021/cr960017t

  133. The calculation of molecular geometrical properties in the Hellmann–Feynman approximation,
    V. Bakken, T. Helgaker, W. Klopper, and K. Ruud,
    Mol. Phys. 96, 653–671 (1999)
    DOI: 10.1080/00268979909483002

  134. Basis-set convergence of the energy in molecular Hartree–Fock calculations,
    A. Halkier, T. Helgaker, P. Jørgensen, W. Klopper, and J. Olsen,
    Chem. Phys. Lett. 302, 437–446 (1999)
    DOI: 10.1016/S0009-2614(99)00179-7

  135. Molecular polarizabilities and magnetizabilities,
    P. Dahle, K. Ruud, T. Helgaker, and P. R. Taylor,
    in Pauling’s Legacy: Modern Modelling of the Chemical Bond,
    Z. B. Maksic and W. J. Orville-Thomas, eds., (Elsevier Science, Amsterdam, 1999), pp. 147–188

  136. Rovibrationally averaged magnetizability, rotational g factor, and indirect spin–spin coupling of the hydrogen fluoride molecule,
    P.-O. Åstrand, K. Ruud, K. V. Mikkelsen, and T. Helgaker,
    J. Chem. Phys. 110, 9463–9468 (1999)
    DOI: 10.1063/1.478912

  137. Solvent effects on the NMR parameters of H2S and HCN,
    K. V. Mikkelsen, K. Ruud, and T. Helgaker,
    J. Comput. Chem. 20, 1281–1291 (1999)
    DOI: 10.1002/(SICI)1096-987X(199909)20:12<1281::AID-JCC8>3.0.CO;2-C

  138. Comment on “Geometry optimization with an infinite basis set” [J. Phys. Chem. A 103 (1999) 651] and “Basis-set extrapolation” [Chem. Phys. Lett. 294 (1998) 45],
    A. Halkier, T. Helgaker, W. Klopper, P. Jørgensen, and A. G. Császár,
    Chem. Phys. Lett. 310, 385–389 (1999)
    DOI: 10.1016/S0009-2614(99)00752-6

  139. Basis-set convergence of the molecular electric dipole moment,
    A. Halkier, W. Klopper, T. Helgaker, and P. Jørgensen,
    J. Chem. Phys. 111, 4424–4430 (1999)
    DOI: 10.1063/1.480036

  140. Basis set convergence of the interaction energy of hydrogen-bonded complexes,
    A. Halkier, W. Klopper, T. Helgaker, P. Jørgensen, and P. R. Taylor,
    J. Chem. Phys. 111, 9157–9167 (1999)
    DOI: 10.1063/1.479830

  141. Grunnlaget for homøopati som behandlingsmetode,
    T. Greibrokk, T. Helgaker, and E. Uggerud,
    Tidsskr. Nor. Lægeforen. 119, 849–851 (1999)

  142. Highly accurate calculations of molecular electronic structure,
    W. Klopper, K. L. Bak, P. Jørgensen, J. Olsen, and T. Helgaker,
    J. Phys. B: At. Mol. Opt. Phys. 32, R103–R130 (1999)
    DOI: 10.1088/0953-4075/32/13/201

    2000

  143. Coupled-cluster singles, doubles and triples (CCSDT) calculations of atomization energies,
    K. L. Bak, P. Jørgensen, J. Olsen, T. Helgaker, and J. Gauss,
    Chem. Phys. Lett. 317, 116–122 (2000)
    DOI: 10.1016/S0009-2614(99)01315-9

  144. Basis-set convergence of the two-electron Darwin term,
    A. Halkier, T. Helgaker, W. Klopper, and J. Olsen,
    Chem. Phys. Lett. 319, 287–295 (2000)
    DOI: 10.1016/S0009-2614(00)00161-5

  145. Perspective on “Neue Berechnung der Energie des Heliums im Grundzustande, sowie des tiefsten Terms von Ortho-Helium” [Hylleraas EA (1929) Z Phys 54: 347–366],
    T. Helgaker and W. Klopper,
    Theor. Chem. Acc. 103, 180–181 (2000)
    DOI: 10.1007/s002149900051

  146. Accuracy of atomization energies and reaction enthalpies in standard and extrapolated electronic wave function/basis set calculations,
    K. L. Bak, P. Jørgensen, J. Olsen, T. Helgaker, and W. Klopper,
    J. Chem. Phys. 112, 9229–9242 (2000)
    DOI: 10.1063/1.481544

  147. Divergence in Møller–Plesset theory: A simple explanation based on a two-state model,
    J. Olsen, P. Jørgensen, T. Helgaker, and O. Christiansen,
    J. Chem. Phys. 112, 9736–9748 (2000)
    DOI: 10.1063/1.481611

  148. Accurate molecular geometries of the protonated water dimer,
    A. A. Auer, T. Helgaker, and W. Klopper,
    Phys. Chem. Chem. Phys. 2, 2235–2238 (2000)
    DOI: 10.1039/a909189k

  149. The accuracy of molecular dipole moments in standard electronic structure calculations,
    K. L. Bak, J. Gauss, T. Helgaker, P. Jørgensen, and J. Olsen,
    Chem. Phys. Lett. 319, 563–568 (2000)
    DOI: 10.1016/S0009-2614(00)00198-6

  150. Molecular Electronic-Structure Theory,
    T. Helgaker, P. Jørgensen, and J. Olsen,
    Wiley, Chichester, 2000 (hardcover); 2013 (paperback)

  151. Should gaseous BF3 and SiF4 be described as ionic compounds?,
    A. Haaland, T. U. Helgaker, K. Ruud, and D. J. Shorokhov,
    J. Chem. Ed. 77, 1076–1080 (2000)
    DOI: 10.1021/ed077p1076

  152. Nuclear shielding constants by density functional theory with gauge including atomic orbitals,
    T. Helgaker, P. J. Wilson, R. D. Amos, and N. C. Handy,
    J. Chem. Phys. 113, 2983–2989 (2000).
    DOI: 10.1063/1.1287056

  153. Direct optimization of the AO density matrix in Hartree–Fock and Kohn–Sham theories,
    T. Helgaker, H. Larsen, J. Olsen, and P. Jørgensen,
    Chem. Phys. Lett. 327, 397–403 (2000)
    DOI: 10.1016/S0009-2614(00)00814-9

  154. Gauge-origin independent magneto-optical activity within coupled cluster response theory,
    S. Coriani, C. Hättig, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 113, 3561–3572 (2000)
    DOI: 10.1063/1.1287833

  155. Hartree–Fock and Kohn–Sham atomic-orbital based time-dependent response theory,
    H. Larsen, P. Jørgensen, J. Olsen, and T. Helgaker
    J. Chem. Phys. 113, 8908–8917 (2000)
    DOI: 10.1063/1.1318745

  156. Analytical calculation of nuclear magnetic resonance indirect spin–spin coupling constants at the generalized gradient approximation and hybrid levels of density-functional theory,
    T. Helgaker, M. Watson, and N. C. Handy,
    J. Chem. Phys. 113, 9402–9409 (2000)
    DOI: 10.1063/1.1321296

    2001

  157. Highly accurate ab initio computation of thermochemical data,
    T. Helgaker, W. Klopper, K. L. Bak, A. Halkier, P. Jørgensen, and J. Olsen,
    in Understanding Chemical Reactivity, Vol. 22: Quantum-Mechanical Prediction of Thermochemical Data,
    J. Cioslowski, ed. (Kluwer, Dordrecht, 2001), pp. 1–30.

  158. The accurate determination of molecular equilibrium structures,
    K. L. Bak, J. Gauss, P. Jørgensen, J. Olsen, T. Helgaker, and J. F. Stanton,
    J. Chem. Phys. 114, 6548–6556 (2001)
    DOI: 10.1063/1.1357225

  159. Chemical accuracy from ‘Coulomb hole’ extrapolated molecular quantum-mechanical calculations,
    K. L. Bak, A. Halkier, P. Jørgensen, J. Olsen, T. Helgaker, and W. Klopper,
    J. Mol. Struct. 567–568, 375–384 (2001)
    DOI: 10.1016/S0022-2860(01)00566-X

  160. Efficient evaluation of one-center three-electron Gaussian integrals,
    P. Wind, T. Helgaker, and W. Klopper,
    Theor. Chem. Acc. 106, 280–286 (2001)
    DOI: 10.1007/s002140100281

  161. Direct perturbation theory of magnetic properties and relativistic corrections for the point nuclear and Gaussian nuclear models,
    A. C. Hennum, W. Klopper, and T. Helgaker,
    J. Chem. Phys. 115, 7356–7363 (2001)
    DOI: 10.1063/1.1405009

  162. Direct optimization of the atomic-orbital density matrix using the conjugate-gradient method with a multilevel preconditioner,
    H. Larsen, J. Olsen, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 115, 9685–9697 (2001)
    DOI: 10.1063/1.1415083

  163. Geometrical derivatives and magnetic properties in atomic-orbital density-based Hartree–Fock theory,
    H. Larsen, T. Helgaker, J. Olsen, and P. Jørgensen,
    J. Chem. Phys. 115, 10344–10352 (2001)
    DOI: 10.1063/1.1415082

    2002

  164. Basis-set completeness profiles in two dimensions,
    A. A. Auer, T. Helgaker, and W. Klopper,
    J. Comput. Chem. 23, 1–6 (2002)
    DOI: 10.1002/jcc.1169

  165. Second-order Møller–Plesset perturbation theory with terms linear in the interelectronic coordinates and exact evaluation of three-electron integrals,
    P. Wind, W. Klopper, and T. Helgaker,
    Theor. Chem. Acc. 107, 173–179 (2002)
    DOI: 10.1007/s00214-001-0318-6

  166. Optical rotation studied by density-functional and coupled-cluster methods,
    K. Ruud and T. Helgaker,
    Chem. Phys. Lett. 352, 533–539 (2002)
    DOI: 10.1016/S0009-2614(01)01492-0

  167. Four-component relativistic Kohn–Sham theory,
    T. Saue and T. Helgaker
    J. Comput. Chem. 23, 814–823 (2002)
    DOI: 10.1002/jcc.10066

  168. Molecular equilibrium structures from experimental rotational constants and calculated vibration–rotation interaction constants,
    F. Pawłowski, P. Jørgensen, J. Olsen, F. Hegelund, T. Helgaker, J. Gauss, K. L. Bak, and J. F. Stanton,
    J. Chem. Phys. 116, 6482–6496 (2002)
    DOI: 10.1063/1.1459782

  169. Parity-violating interaction in H2O2 calculated from density-functional theory,
    A. C. Hennum, T. Helgaker, and W. Klopper,
    Chem. Phys. Lett. 354, 274–282 (2002)
    DOI: 10.1016/S0009-2614(02)00111-2

  170. Vibronic transitions from coupled-cluster response theory: Theory and application to HSiF and H2O,
    O. Christiansen, T. A. Ruden, K. Ruud, and T. Helgaker,
    J. Chem. Phys. 116, 8334–8342 (2002)
    DOI: 10.1063/1.1468639

  171. Gauge-origin independent density-functional theory calculations of vibrational Raman optical activity,
    K. Ruud, T. Helgaker, and P. Bouř,
    J. Phys. Chem. A. 106, 7448–7455 (2002)
    DOI: 10.1021/jp026037i

  172. Spin–spin coupling tensors by density-functional linear response theory,
    P. Lantto, J. Vaara, and T. Helgaker,
    J. Chem. Phys. 117, 5998–6009 (2002)
    DOI: 10.1063/1.1502243

  173. Et virtuelt laboratorium: Kjemi på datamaskinen,
    T. Helgaker,
    Apollon Nr. 3, 2002, pp. 27–29


  174. Computation of two-electron Gaussian integrals for wave functions including the correlation factor r12exp(–γr212),
    C. C. M. Samson, W. Klopper, and T. Helgaker,
    Comp. Phys. Comm. 149, 1–10 (2002)
    DOI: 10.1016/S0010-4655(02)00590-8

  175. The efficient optimization of molecular geometries using redundant internal coordinates,
    V. Bakken and T. Helgaker,
    J. Chem. Phys. 117, 9160–9174 (2002)
    DOI: 10.1063/1.1515483

  176. Density-functional theory of linear and nonlinear time-dependent molecular properties,
    P. Sałek, O. Vahtras, T. Helgaker, and H. Ågren,
    J. Chem. Phys. 117, 9630–9645 (2002)
    DOI: 10.1063/1.1516805

    2003

  177. Accuracy of spectroscopic constants of diatomic molecules from ab initio calculations,
    F. Pawłowski, A. Halkier, P. Jørgensen, K. L. Bak, T. Helgaker, and W. Klopper,
    J. Chem. Phys. 118, 2539–2549 (2003)
    DOI: 10.1063/1.1533032

  178. A Lagrangian, integral-density direct formulation and implementation of the analytic CCSD and CCSD(T) gradients,
    K. Hald, A. Halkier, P. Jørgensen, S. Coriani, C. Hättig, and T. Helgaker,
    J. Chem. Phys. 118, 2985–2998 (2003);
    DOI: 10.1063/1.1531106
    Publisher’s Note: “A Lagrangian, integral-density direct formulation and implementation of the analytic CCSD and CCSD(T) gradients” [J. Chem. Phys. 118, 2985 (2003)],
    K. Hald, A. Halkier, P. Jørgensen, S. Coriani, C. Hättig, and T. Helgaker,
    J. Chem. Phys. 118, 11335–11335 (2003)
    DOI: 10.1063/1.1580103

  179. The spin–spin coupling constants in ethane, methanol and methylamine: a comparison of DFT, MCSCF and CCSD results,
    M. Pecul and T. Helgaker,
    Int. J. Mol. Sci. 4, 143–157 (2003)
    DOI: 10.3390/i4030143

  180. Coupled-cluster connected-quadruples corrections to atomization energies,
    T. A. Ruden, T. Helgaker, P. Jørgensen, and J. Olsen,
    Chem. Phys. Lett. 371, 62–67 (2003)
    DOI: 10.1016/S0009-2614(03)00225-2

  181. Sternheimer shieldings and EFG polarizabilities: a density-functional theory study,
    A. Rizzo, K. Ruud, T. Helgaker, P. Sałek, H. Ågren, and O. Vahtras,
    Chem. Phys. Lett. 372, 377–385 (2003)
    DOI: 10.1016/S0009-2614(03)00410-X

  182. Calculations of hydrogen-bond-transmitted indirect nuclear spin–spin couplings: a comparison of density-functional and ab initio methods,
    M. Pecul, J. Sadlej, and T. Helgaker,
    Chem. Phys. Lett. 372, 476–484 (2003)
    DOI: 10.1016/S0009-2614(03)00475-5

  183. Vibrational corrections to indirect nuclear spin–spin coupling constants calculated by density-functional theory,
    T. A. Ruden, O. B Lutnæs, T. Helgaker, and K. Ruud,
    J. Chem. Phys. 118, 9572–9581 (2003)
    DOI: 10.1063/1.1569846

  184. Density-functional theory calculation of the nuclear magnetic resonance indirect nuclear spin–spin coupling constants in C60,
    M. Jaszuński, K. Ruud, and T. Helgaker,
    Mol. Phys. 101, 1997–2002 (2003)
    DOI: 10.1080/0026897031000109301

  185. Wave function-based quantum chemistry,
    T. Helgaker, P. Jørgensen, J. Olsen, and W. Klopper,
    in Computational Medicinal Chemistry for Drug Discovery,
    P. Bultinck, H. De Winter, W. Langenaeker, and J. Tollenaere eds., (Marcel Dekker, 2003), pp. 57–88

  186. Automated calculation of fundamental frequencies: Application to AlH3 using the coupled-cluster singles-and-doubles with perturbative triples method,
    T. A. Ruden, P. R. Taylor, and T. Helgaker,
    J. Chem. Phys. 119, 1951–1960 (2003)
    DOI: 10.1063/1.1583671

  187. Calculations of two-photon absorption cross sections by means of density-functional theory,
    P. Sałek, O. Vahtras, J. Guo, Y. Luo, T. Helgaker, and H. Ågren,
    Chem. Phys. Lett. 374, 446–452 (2003)
    DOI: 10.1016/S0009-2614(03)00681-X

  188. Characterization of dihydrogen-bonded D–H···H–A complexes on the basis of infrared and magnetic resonance spectroscopic parameters,
    H. Cybulski, M. Pecul, J. Sadlej, and T. Helgaker,
    J. Chem. Phys. 119, 5094–5104 (2003)
    DOI: 10.1063/1.1597633

  189. Density functional theory of nonlinear triplet response properties with applications to phosphorescence,
    I. Tunell, Z. Rinkevicius, O. Vahtras, P. Sałek, T. Helgaker, and H. Ågren,
    J. Chem. Phys. 119, 11024–11034 (2003)
    DOI: 10.1063/1.1622926

    2004

  190. The NMR indirect nuclear spin–spin coupling constants for some small rigid hydrocarbons: molecular equilibrium values and vibrational corrections,
    T. A. Ruden, T. Helgaker, and M. Jaszuński,
    Chem. Phys. 296, 53–62 (2004)
    DOI: 10.1016/j.chemphys.2003.08.018

  191. Density functional theory calculation of electronic circular dichroism using London orbitals,
    M. Pecul, K. Ruud, and T. Helgaker,
    Chem. Phys. Lett. 388, 110–119 (2004)
    DOI: 10.1016/j.cplett.2004.03.008

  192. Potential energy and spin–spin coupling constants surface of glycolaldehyde,
    T. Ratajczyk, M. Pecul, J. Sadlej, and T. Helgaker,
    J. Phys. Chem. A 108, 2758–2769 (2004)
    DOI: 10.1021/jp0375315

  193. Calculation of electric dipole hypershieldings at the nuclei in the Hellmann–Feynman approximation,
    A. Soncini, P. Lazzeretti, V. Bakken, and T. Helgaker,
    J. Chem. Phys. 120, 3142–3151 (2004)
    DOI: 10.1063/1.1630016

  194. Density-functional theory calculations of optical rotatory dispersion in the nonresonant and resonant frequency regions,
    P. Norman, K. Ruud, and T. Helgaker,
    J. Chem. Phys. 120, 5027–5035 (2004)
    DOI: 10.1063/1.1647515

  195. Density-functional generalized-gradient and hybrid calculations of electromagnetic properties using Slater basis sets,
    M. A. Watson, N. C. Handy, A. J. Cohen, and T. Helgaker,
    J. Chem. Phys. 120, 7252–7261 (2004)
    DOI: 10.1063/1.1668633

  196. Spin–spin coupling constants with HF and DFT methods,
    T. Helgaker and M. Pecul,
    In Calculation of NMR and EPR Parameters: Theory and Applications,
    M. Kaupp, M. Bühl, and V. G. Malkin, eds. (Wiley-VCH, Weinheim 2004), pp. 101–121

  197. Conformational effects on the optical rotation of alanine and proline,
    M. Pecul, K. Ruud, A. Rizzo, and T. Helgaker,
    J. Phys. Chem. A 108, 4269–4276 (2004)
    DOI: 10.1021/jp037663y

  198. The trust-region self-consistent field method: Towards a black-box optimization in Hartree–Fock and Kohn–Sham theories,
    L. Thøgersen, J. Olsen, D. Yeager, P. Jørgensen, P. Sałek, and T. Helgaker,
    J. Chem. Phys. 121, 16–27 (2004)
    DOI: 10.1063/1.1755673

  199. GIAO shielding constants and indirect spin–spin coupling constants: performance of density functional methods,
    T. W. Keal, D. J. Tozer, and T. Helgaker,
    Chem. Phys. Lett. 391, 374 –379 (2004)
    DOI: 10.1016/j.cplett.2004.04.108

  200. Linear-scaling formation of Kohn-Sham Hamiltonian: Application to the calculation of excitation energies and polarizabilities of large molecular systems,
    M. A. Watson, P. Sałek, P. Macak, and T. Helgaker,
    J. Chem. Phys. 121, 2915–2931 (2004)
    DOI: 10.1063/1.1771639 ">

  201. Polarization consistent basis sets. V. The elements Si–Cl,
    F. Jensen and T. Helgaker,
    J. Chem. Phys. 121, 3463–3470 (2004)
    DOI: 10.1063/1.1756866

  202. The expansion of hydrogen states in Gaussian orbitals,
    V. Bakken and T. Helgaker,
    Theor. Chem. Acc. 112, 124–134 (2004)
    DOI: 10.1007/s00214-004-0573-4

  203. The calculation of indirect nuclear spin–spin coupling constants in large molecules,
    M. A. Watson, P. Sałek, P. Macak, M. Jaszuński, and T. Helgaker,
    Chem. Eur. J. 10, 4627–4639 (2004)
    DOI: 10.1002/chem.200306065

  204. A priori calculation of molecular properties to chemical accuracy,
    T. Helgaker, T. A. Ruden, P. Jørgensen, J. Olsen, and W. Klopper,
    J. Phys. Org. Chem. 17, 913–933 (2004)
    DOI: 10.1002/poc.841

  205. The performance of hybrid density functional theory for the calculation of indirect nuclear spin–spin coupling constants in substituted hydrocarbons,
    O. B. Lutnæs T. A. Ruden, and T. Helgaker,
    Magn. Reson. Chem. 42, S117–S127 (2004)
    DOI: 10.1002/mrc.1457

  206. Coupled-cluster connected quadruples and quintuples corrections to the harmonic vibrational frequencies and equilibrium bond distances of HF, N2, F2, and CO,
    T. A. Ruden, T. Helgaker, P. Jørgensen, and J. Olsen,
    J. Chem. Phys. 121, 5874–5884 (2004)
    DOI: 10.1063/1.1780155

  207. A closed-shell coupled-cluster treatment of the Breit–Pauli first-order relativistic energy correction,
    S. Coriani, T. Helgaker, P. Jørgensen, and W. Klopper,
    J. Chem. Phys. 121, 6591–6598 (2004)
    DOI: 10.1063/1.1788634

  208. First-order relativistic corrections to response properties: the hyperpolarizability of the Ne atom,
    W. Klopper, S. Coriani, T. Helgaker, and P. Jørgensen,
    J. Phys. B: At. Mol. Opt. Phys. 37, 3753–3763 (2004)
    DOI: 10.1088/0953-4075/37/18/015

  209. Models of fragmentations induced by electron attachment to protonated peptides,
    V. Bakken, T. Helgaker, and E. Uggerud,
    Eur. J. Mass Spectrom. 10, 625–638 (2004)
    DOI: 10.1255/ejms.665

  210. A comparison of polarization and bond functions for density functional calculations,
    J. Bruun, T. Helgaker, and F. Jensen,
    Mol. Phys. 102, 2559-2562 (2004)
    DOI: 10.1080/0026897042000275026

    2005

  211. A comparison of density-functional-theory and coupled-cluster frequency-dependent polarizabilities and hyperpolarizabilities,
    P. Sałek, T. Helgaker, O. Vahtras, H. Ågren, D. Jonsson, and J. Gauss,
    Mol. Phys. 103, 439–450 (2005)
    DOI: 10.1080/00268970412331319254

  212. Linear response at the 4-component relativistic density-functional level: application to the frequency-dependent dipole polarizability of Hg, AuH and PtH2,
    P. Sałek, T. Helgaker, and T. Saue,
    Chem. Phys. 311, 187–201 (2005)
    DOI: 10.1016/j.chemphys.2004.10.011

  213. Atmospheric chemistry of CHF2CHO: Study of the IR and UV–vis absorption cross sections, photolysis, and OH-, Cl-, and NO3-initiated oxidation,
    S. R. Sellevåg, Y. Stenstrøm, T. Helgaker, and C. J. Nielsen,
    J. Phys. Chem. A 109, 3652–3662 (2005)
    DOI: 10.1021/jp050313m

  214. Theoretical studies of nuclear magnetic resonance parameters for the proton-exchange pathways in porphyrin and porphycene,
    H. Cybulski, M. Pecul, T. Helgaker, and M. Jaszuński,
    J. Phys. Chem. A 109, 4162–4171 (2005)
    DOI: 10.1021/jp045440h

  215. Density-functional theory study of electric and magnetic properties of hexafluorobenzene in the vapor phase,
    A. Rizzo, C. Cappelli, B. Jansík, D. Jonsson, P. Sałek, S. Coriani, D. J. D. Wilson, T. Helgaker, and H. Ågren,
    J. Chem. Phys. 122, 234314 (2005),
    DOI: 10.1063/1.1935513
    Erratum, J. Chem. Phys. 129, 039901 (2008)
    DOI: 10.1063/1.2946699

  216. The trust-region self-consistent field method in Kohn–Sham density-functional theory,
    L. Thøgersen, J. Olsen, A. Köhn, P. Jørgensen, P. Sałek, and T. Helgaker,
    J. Chem. Phys. 123, 074103 (2005)
    DOI: 10.1063/1.1989311

  217. The rotational g tensor as a benchmark for density-functional theory calculations of molecular magnetic properties,
    D. J. D. Wilson, C. E. Mohn, and T. Helgaker,
    J. Chem. Theory Comput. 1, 877–888 (2005)
    DOI: 10.1021/ct050101t

  218. A computational study of some electric and magnetic properties of gaseous BF3 and BCl3,
    A. Rizzo, C. Cappelli, J. M. Junquera-Hernández, A. M. J. Sánchez de Merás, J. Sánchez-Marín, D. J. D. Wilson, and T. Helgaker,
    J. Chem. Phys. 123, 114307 (2005),
    DOI: 10.1063/1.2034487
    Erratum, J. Chem. Phys. 129, 039901 (2008)
    DOI: 10.1063/1.2946699

  219. The accuracy of ab initio molecular geometries for systems containing second-row atoms,
    S. Coriani, D. Marchesan, J. Gauss, C. Hättig, T. Helgaker, and P. Jørgensen,
    J. Chem. Phys. 123, 184107 (2005)
    DOI: 10.1063/1.2104387

  220. Calculations of two-photon charge-transfer excitations using Coulomb-attenuated density-functional theory,
    E. Rudberg, P. Sałek, T. Helgaker, and H. Ågren,
    J. Chem. Phys. 123, 184108 (2005)
    DOI: 10.1063/1.2104367

  221. The rotational g tensor as a benchmark for ab initio molecular property calculations,
    C. E. Mohn, D. J. D. Wilson, O. B. Lutnæs, T. Helgaker, and K. Ruud,
    Adv. In Quantum Chem. 50, 77–90 (2005)
    DOI: 10.1016/S0065-3276(05)50005-4

  222. Quadratic response functions in a second-order polarization propagator framework,
    J. Olsen, P. Jørgensen, T. Helgaker, and J. Oddershede,
    J. Phys. Chem. A 109, 11618–11628 (2005)
    DOI: 10.1021/jp054207w

    2006

  223. The equilibrium structure of ferrocene,
    S. Coriani, A. Haaland, T. Helgaker, and P. Jørgensen,
    ChemPhysChem 7, 245–249 (2006)
    DOI: 10.1002/cphc.200500339

  224. Assessment of a Coulomb-attenuated exchange–correlation energy functional,
    M. J. G. Peach, T. Helgaker, P. Sałek, T. W. Keal, O. B. Lutnæs, D. J. Tozer, and N. C. Handy,
    Phys. Chem. Chem. Phys. 8, 558–562 (2006)
    DOI: 10.1039/b511865d

  225. Benchmarking two-photon absorption with CC3 quadratic response theory, and comparison with density-functional response theory,
    M. J. Paterson, O. Christiansen, F. Pawłowski, P. Jørgensen, C. Hättig, T. Helgaker, and P. Sałek,
    J. Chem. Phys. 124, 054322 (2006)
    DOI: 10.1063/1.2163874

  226. The magnetizability, rotational g tensor and quadrupole moment of the boron trihalides,
    D. J. D. Wilson, T. Helgaker, and A. Rizzo,
    Mol. Phys. 104, 847–856 (2006)
    DOI: 10.1080/00268970500418117

  227. Rotational g tensors calculated using hybrid exchange-correlation functionals with the optimized effective potential approach,
    O. B. Lutnæs, A. M. Teale, T. Helgaker, and D. J. Tozer,
    J. Chem. Theory Comput. 2, 827–834 (2006)
    DOI: 10.1021/ct060038n

  228. Choice of exchange-correlation functional for computing NMR indirect spin–spin coupling constants,
    T. W. Keal, T. Helgaker, P. Sałek, and D. J. Tozer,
    Chem. Phys. Lett. 425, 163–166 (2006)
    DOI: 10.1016/j.cplett.2006.05.032

  229. Density-functional-theory study of the electric-field-induced second harmonic generation (EFISHG) of push–pull phenylpolyenes in solution,
    L. Ferrighi, L. Frediani, C. Cappelli, P. Sałek, H. Ågren, T. Helgaker, and K. Ruud,
    Chem. Phys. Lett. 425, 267–272 (2006)
    DOI: 10.1016/j.cplett.2006.04.112

  230. A second-quantization framework for the unified treatment of relativistic and nonrelativistic molecular perturbations by response theory,
    T. Helgaker, A. C. Hennum, and W. Klopper,
    J. Chem. Phys. 125, 024102 (2006)
    DOI: 10.1063/1.2198527

  231. Towards black-box linear scaling optimization in Hartree-Fock and Kohn-Sham theories,
    S. Høst, J. Olsen, B. Jansík, P. Jørgensen, S. Reine, T. Helgaker, P. Sałek, and S. Coriani,
    in Lecture Series on Computer and Computational Sciences, Vol. 6: Trends and Perspectives in Modern Computational Science,
    G. Maroulis and T. E. Simos, eds. (Brill Academic Publishers, Leiden, 2006), pp. 177–189
    DOI: 10.1201/b12251-12

  232. Self-consistent field methods applied to large molecular systems,
    T. Helgaker, F. Pawlowski, S. Reine, S. Høst, B. Jansík, J. Olsen, P. Jørgensen, S. Coriani, and P. Sałek,
    in Lecture Series on Computer and Computational Sciences, Vol. 7: Recent Progress in Computational Sciences and Engineering,
    G. Maroulis and T. E. Simos, eds. (Brill Academic Publishers, Leiden, 2006), pp. 1297–1297
    DOI: 10.1201/b12066-142

    2007

  233. Density-functional and coupled-cluster singles-and-doubles calculations of the nuclear shielding and indirect nuclear spin–spin coupling constants of o-benzyne,
    T. Helgaker, O. B. Lutnæs, and M. Jaszuński,
    J. Chem. Theory Comput. 3, 86–94 (2007)
    DOI: 10.1021/ct600234n

  234. Electron correlation: the many-body problem at the heart of chemistry,
    D. P. Tew, W. Klopper, and T. Helgaker,
    J. Comput. Chem. 28, 1307–1320 (2007)
    DOI: 10.1002/jcc.20581

  235. Linear-scaling implementation of molecular electronic self-consistent field theory,
    P. Sałek, S. Høst, L. Thøgersen, P. Jørgensen, P. Manninen, J. Olsen, B. Jansík, S. Reine, F. Pawłowski, E. Tellgren, T. Helgaker, and S. Coriani,
    J. Chem. Phys. 126, 114110 (2007)
    DOI: 10.1063/1.2464111

  236. Linear-scaling symmetric square-root decomposition of the overlap matrix,
    B. Jansík, S. Høst, P. Jørgensen, J. Olsen, and T. Helgaker,
    J. Chem. Phys. 126, 124104 (2007)
    DOI: 10.1063/1.2709881

  237. Linear-scaling implementation of molecular response theory in self-consistent field electronic-structure theory,
    S. Coriani, S. Høst, B. Jansík, L. Thøgersen, J. Olsen, P. Jørgensen, S. Reine, F. Pawłowski, T. Helgaker, and P. Sałek,
    J. Chem. Phys. 126, 154108 (2007)
    DOI: 10.1063/1.2715568

  238. Accurate quantum-chemical calculations using Gaussian-type geminal and Gaussian-type orbital basis sets: applications to atoms and diatomics,
    P. Dahle, T. Helgaker, D. Jonsson, and P. R. Taylor,
    Phys. Chem. Chem. Phys. 9, 3112–3126 (2007)
    DOI: 10.1039/b616488a

  239. A unified scheme for the calculation of differentiated and undifferentiated molecular integrals over solid-harmonic Gaussians,
    S. Reine, E. Tellgren, and T. Helgaker,
    Phys. Chem. Chem. Phys. 9, 4771–4779 (2007)
    DOI: 10.1039/b705594c

  240. Electronic circular dichroism of disulphide bridge: Ab initio quantum-chemical calculations,
    W. Skomorowski, M. Pecul, P. Sałek, and T. Helgaker,
    J. Chem. Phys. 127, 085102 (2007)
    DOI: 10.1063/1.2759203

  241. Structural and electronic properties of polyacetylene and polyyne from hybrid and Coulomb-attenuated density functionals,
    M. J. G. Peach, E. I. Tellgren, P. Sałek, T. Helgaker, and D. J. Tozer,
    J. Phys. Chem. A 111, 11930–11935 (2007)
    DOI: 10.1021/jp0754839

  242. Explicit electron correlation by a combined use of Gaussian-type orbitals and Gaussian-type geminals,
    P. Dahle, T. Helgaker, D. Jonsson, and P. R. Taylor,
    in Computation in Modern Science and Engineering, Proceedings of the International Conference on Computational Methods in Science and Engineering 2007,
    G. Maroulis and T. E. Simos, eds. (American Institute of Physics 2007), Vol. 2 Part A, pp. 187–190
    DOI: 10.1063/1.2836035

    2008

  243. Static and frequency-dependent dipole–dipole polarizabilities of all closed-shell atoms up to radium: A four-component relativistic DFT study,
    R. Bast, A. Heßelmann, P. Sałek, T. Helgaker, and T. Saue,
    ChemPhysChem 9, 445–453 (2008)
    DOI: 10.1002/cphc.200700504

  244. Excitation energies in density functional theory: An evaluation and a diagnostic test,
    M. J. G. Peach, P. Benfield, T. Helgaker, and D. J. Tozer,
    J. Chem. Phys. 128, 044118 (2008)
    [Supplementary Information: EPAPS Document No. E-JCPSA6-128-029805]
    DOI: 10.1063/1.2831900

  245. Second-order Møller–Plesset calculations on the water molecule using Gaussian-type orbital and Gaussian-type geminal theory,
    P. Dahle, T. Helgaker, D. Jonsson, and P. R. Taylor,
    Phys. Chem. Chem. Phys. 10, 3377–3382 (2008)
    DOI: 10.1039/b803577f

  246. Erratum: “Density-functional and electron correlated study of five linear birefringences—Kerr, Cotton–Mouton, Buckingham, Jones and magnetoelectric—in gaseous benzene” [J. Chem. Phys. 121, 8814 (2004)]; “Density-functional study of electric and magnetic properties of hexafluorobenzene in the vapor phase” [J. Chem. Phys. 122, 234314 (2005)]; and “A computational study of some electric and magnetic properties of gaseous BF3 and BCl3” [J. Chem. Phys. 123, 114307 (2005)],
    A. Rizzo, C. Cappelli, B. Jansík, D. Jonsson, P. Sałek, S. Coriani, H. Ågren, D. J. D. Wilson, T. Helgaker, J. M. Junquera–Hernández, A. M. J. Sánchez de Merás, and J. Sánchez-Marín,
    J. Chem. Phys. 129, 039901 (2008)
    DOI: 10.1063/1.2946699

  247. Hartree-Fock and Kohn-Sham time-dependent response theory in a second-quantization atomic-orbital formalism suitable for linear scaling,
    T. Kjærgaard, P. Jørgensen, J. Olsen, S. Coriani, and T. Helgaker,
    J. Chem. Phys. 129, 054106 (2008)
    DOI: 10.1063/1.2961039

  248. Maps of current density using density-functional methods,
    A. Soncini, A. M. Teale, T. Helgaker, F. De Proft, and D. J. Tozer,
    J. Chem. Phys. 129, 074101 (2008)
    DOI: 10.1063/1.2969104

  249. The quantum-chemical calculation of NMR indirect spin–spin coupling constants,
    T. Helgaker, M. Jaszuński, and M. Pecul,
    Prog. Nucl. Magn. Reson. Spectrosc. 53, 249–268 (2008)
    DOI: 10.1016/j.pnmrs.2008.02.002

  250. A ground-state-directed optimization scheme for the Kohn–Sham energy,
    S. Høst, B. Jansík, J. Olsen, P. Jørgensen, S. Reine, and T. Helgaker,
    Phys. Chem. Chem. Phys. 10, 5344–5348 (2008)
    DOI: 10.1039/b807639a

  251. Variational and robust density fitting of four-center two-electron integrals in local metrics,
    S. Reine, E. Tellgren, A. Krapp, T. Kjærgaard, T. Helgaker, B. Jansík, S. Høst, and P. Sałek,
    J. Chem. Phys. 129, 104101 (2008)
    DOI: 10.1063/1.2956507

  252. The augmented Roothaan–Hall method for optimizing Hartree–Fock and Kohn–Sham density matrices,
    S. Høst, J. Olsen, B. Jansík, L. Thøgersen, P. Jørgensen, and T. Helgaker,
    J. Chem. Phys. 129, 124106 (2008)
    DOI: 10.1063/1.2974099

  253. Nonperturbative ab initio calculations in strong magnetic fields using London orbitals,
    E. I. Tellgren, A. Soncini, and T. Helgaker,
    J. Chem. Phys. 129, 154114 (2008)
    DOI: 10.1063/1.2996525

  254. Quantitative quantum chemistry,
    T. Helgaker, W. Klopper, and D. P. Tew,
    Mol. Phys. 106, 2107–2143 (2008)
    DOI: 10.1080/00268970802258591

  255. Density-functional calculations of the nuclear magnetic shielding and indirect nuclear spin–spin coupling constants of three isomers of C20,
    O. B. Lutnæs, T. Helgaker, and M. Jaszuński,
    Mol. Phys. 106, 2357–2365 (2008)
    DOI: 10.1080/00268970802467994

  256. Efficient elimination of response parameters in molecular property calculations for variational and nonvariational energies,
    K. Kristensen, P. Jørgensen, A. J. Thorvaldsen, and T. Helgaker,
    J. Chem. Phys. 129, 214103 (2008)
    DOI: 10.1063/1.3023123

    2009

  257. The geminal basis in explicitly correlated wave functions,
    S. Höfener, D. P. Tew, W. Klopper, and T. Helgaker,
    Chem. Phys. 356, 25–30 (2009)
    DOI: 10.1016/j.chemphys.2008.10.022

  258. The calculation of adiabatic-connection curves from full configuration-interaction densities: Two-electron systems,
    A. M. Teale, S. Coriani, and T. Helgaker,
    J. Chem. Phys. 130, 104111 (2009)
    DOI: 10.1063/1.3082285

  259. Robust and reliable multilevel minimization of the Kohn–Sham energy,
    B. Jansík, S. Høst, M. P. Johansson, J. Olsen, P. Jørgensen, and T. Helgaker,
    J. Chem. Theory Comput. 5, 1027–1032 (2009)
    DOI: 10.1021/ct800562h

  260. Non-perturbative magnetic phenomena in closed-shell paramagnetic molecules,
    E. I. Tellgren, T. Helgaker, and A. Soncini,
    Phys. Chem. Chem. Phys. 11, 5489–5498 (2009)
    DOI: 10.1039/b822262b

  261. A stepwise atomic, valence-molecular, and full-molecular optimisation of the Hartree–Fock/Kohn–Sham energy,
    B. Jansík, S. Høst, M. P. Johansson, J. Olsen, P. Jørgensen, and T. Helgaker,
    Phys. Chem. Chem. Phys. 11, 5805–5813 (2009)
    DOI: 10.1039/b901987a

  262. Benchmarking density-functional-theory calculations of rotational g tensors and magnetizabilities using accurate coupled-cluster calculations,
    O. B. Lutnæs, A. M. Teale, T. Helgaker, D. J. Tozer, K. Ruud, and J. Gauss,
    J. Chem. Phys. 131, 144104 (2009)
    [Supplementary Information: EPAPS Document No. E-JCPSA6-131-007939]
    DOI: 10.1063/1.3242081

  263. Implementation of the incremental scheme for one-electron first-order properties in coupled-cluster theory,
    J. Friedrich, S. Coriani, T. Helgaker, and M. Dolg,
    J. Chem. Phys. 131, 154102 (2009)
    [Supplementary Information: EPAPS Document No. E-JCPSA6-131-038939]
    DOI: 10.1063/1.3243864

  264. Assessment of theoretical methods for the determination of the mechanochemical strength of covalent bonds,
    M. F. Iozzi, T. Helgaker, and E. Uggerud,
    Mol. Phys. 107, 2537–2546 (2009)
    DOI: 10.1080/00268970903401041

    2010

  265. Accurate calculation and modelling of the adiabatic connection in density functional theory,
    A. M. Teale, S. Coriani, and T. Helgaker,
    J. Chem. Phys. 132, 164115 (2010)
    DOI: 10.1063/1.3380834

  266. An efficient density-functional-theory force evaluation for large molecular systems,
    S. Reine, A. Krapp, M. F. Iozzi, V. Bakken, T. Helgaker, F. Pawłowski, and P. Sałek,
    J. Chem. Phys. 133, 044102 (2010)
    DOI: 10.1063/1.3459061

  267. Range-dependent adiabatic connections,
    A. M. Teale, S. Coriani, and T. Helgaker,
    J. Chem. Phys. 133, 164112 (2010)
    DOI: 10.1063/1.3488100

  268. Spin–spin coupling constants and triplet instabilities in Kohn–Sham theory,
    O. B. Lutnæs, M. Jaszuński, and T. Helgaker,
    Mol. Phys. 108, 2579–2590 (2010)
    DOI: 10.1080/00268976.2010.513344

  269. The scientific case for eInfrastructure in Norway,
    G. Gisler, E. Celledoni, T. U. Helgaker, T. Iversen, K. S. Jakobsen, C. Jones, A. Lipniacka, A. Lundervold, N. R. B. Olsen, and K. De Smedt,
    The Research Council of Norway, Oslo, 2010 (ISBN 978-82-12-02831-9)

    2011

  270. The ab initio calculation of molecular electric, magnetic and geometric properties,
    R. Bast, U. Ekström, B. Gao, T. Helgaker, K. Ruud, and A. J. Thorvaldsen,
    Phys. Chem. Chem. Phys. 13, 2627–2651 (2011)
    DOI: 10.1039/c0cp01647k

  271. Influence of external force on properties and reactivity of disulfide bonds,
    M. F. Iozzi, T. Helgaker, and E. Uggerud,
    J. Phys. Chem. A 115, 2308–2315 (2011)
    DOI: 10.1021/jp109428g

  272. Relativistic four-component calculations of Buckingham birefringence using London atomic orbitals,
    R. Bast, K. Ruud, A. Rizzo, and T. Helgaker,
    Theor. Chem. Acc. 129, 685–699 (2011)
    DOI: 10.1007/s00214-011-0939-3

  273. Spin flipping in ring-coupled-cluster-doubles theory,
    W. Klopper, A. M. Teale, S. Coriani, T. B. Pedersen, and T. Helgaker,
    Chem. Phys. Lett. 510, 147–153 (2011)
    DOI: 10.1016/j.cplett.2011.04.101

  274. Molecules in strong magnetic fields,
    T. Helgaker, K. K. Lange, and E. I. Tellgren
    Meta, No. 3, 2011, pp. 16–18

  275. Chemistry and materials,
    T. Helgaker,
    Kjemi, No. 5, 2011, pp. 10–11,
    Reprinted from: The scientific case for eInfrastructure in Norway, The Research Council of Norway, Oslo, 2010

  276. Dispersion interactions in density-functional theory: An adiabatic-connection analysis,
    M. D. Strømsheim, N. Kumar, S. Coriani, E. Sagvolden, A. M. Teale, and T. Helgaker,
    J. Chem. Phys. 135, 194109 (2011)
    DOI: 10.1063/1.3660357

    2012

  277. A theoretical study on hydrogen transport mechanism in SrTiO3 perovskite,
    T. Onishi and T. Helgaker,
    Int. J. Quantum Chem. 112, 201–207 (2012)
    DOI: 10.1002/qua.24086

  278. Recent advances in wave function-based methods of molecular-property calculations,
    T. Helgaker, S. Coriani, P. Jørgensen, K. Kristensen, J. Olsen, and K. Ruud,
    Chem. Rev. 112, 543–631 (2012)
    DOI: 10.1021/cr2002239

  279. Multi-electron integrals,
    S. Reine, T. Helgaker, and R. Lindh,
    WIREs Comput. Mol. Sci. 2, 290–303 (2012)
    DOI: 10.1002/wcms.78

  280. Calculation of the two-electron Darwin term using explicitly correlated wave functions,
    N. Middendorf, S. Höfener, W. Klopper, and T. Helgaker,
    Chem. Phys. 401, 146–151 (2012)
    DOI: 10.1016/j.chemphys.2011.10.035

  281. Analytical GIAO and hybrid-basis integral derivatives: application to geometry optimization of molecules in strong magnetic fields,
    E. I. Tellgren, S. S. Reine, and T. Helgaker,
    Phys. Chem. Chem. Phys. 14, 9492–9499 (2012)
    DOI: 10.1039/c2cp40965h

  282. A paramagnetic bonding mechanism for diatomics in strong magnetic fields,
    K. K. Lange, E. I. Tellgren, M. R. Hoffmann, and T. Helgaker,
    Science 337, 327–331 (2012)
    DOI: 10.1126/science.1219703

  283. Special issue in honour of Peter R. Taylor: Foreword,
    J. Gauss, T. Helgaker, and J. Stanton,
    Mol. Phys. 110, 2313–2313 (2012)
    DOI: 10.1080/00268976.2012.731766

  284. The NMR indirect nuclear spin–spin coupling constant of the HD molecule,
    T. Helgaker, M. Jaszuński, P. Garbacz, and K. Jackowski,
    Mol. Phys. 110, 2611–2617 (2012)
    DOI: 10.1080/00268976.2012.729097

  285. Range-dependent adiabatic connections,
    A. M. Teale, S. Coriani, and T. Helgaker,
    AIP Conf. Proc. 1504, 92–99 (2012)
    DOI: 10.1063/1.4771706

  286. Choice of basic variables in current-density-functional theory,
    E. I. Tellgren, S. Kvaal, E. Sagvolden, U. Ekström, A. M. Teale, and T. Helgaker,
    Phys. Rev. A 86, 062506 (2012)
    DOI: 10.1103/PhysRevA.86.062506

  287. Petascaling and Performance Analysis of DALTON on Different Platforms,
    S. Reine, T. Kjærgaard, T. Helgaker, O.Vahtras, Z. Rinkevicius, B. Frecus, T. W. Keal, A. Sunderland, P. Sherwood, M Schliephake, X. Aguilar, L. Axner, M. F. Iozzi, O. W. Saastad, J. Gimenez,
    Whitepaper of the Partnership for Advanced Computing in Europe (PRACE). September 2012.

    2013

  288. Benchmarking density-functional theory calculations of NMR shielding constants and spin–rotation constants using accurate coupled-cluster calculations,
    A. M. Teale, O. B. Lutnæs, T. Helgaker, D. J. Tozer, and J. Gauss,
    J. Chem. Phys. 138, 024111 (2013)
    DOI: 10.1063/1.4773016

  289. A theoretical study on the hydrogen transport mechanism in SrTiO3 perovskite. II. Scandium doping at titanium site,
    T. Onishi and T. Helgaker,
    Int. J. Quantum Chem. 113, 599–604 (2013)
    DOI: 10.1002/qua.24086

  290. Insights into the dynamics of evaporation and proton migration in protonated water clusters from large-scale Born–Oppenheimer direct dynamics,
    V. V. Rybkin, A. O. Simakov, V. Bakken, S. Reine, T. Kjærgaard, T. Helgaker, and E. Uggerud,
    J. Comp. Chem. 34, 533–544 (2013)
    DOI: 10.1002/jcc.23162

  291. Attractive electron–electron interactions within robust local fitting approximations,
    P. Merlot, T. Kjærgaard, T. Helgaker, R. Lindh, F. Aquilante, S. Reine, and T. B. Pedersen,
    J. Comp. Chem. 34, 1486–1496 (2013)
    DOI: 10.1002/jcc.23284

  292. Internal-to-Cartesian back transformation of molecular geometry steps using high-order geometric derivatives,
    V. V. Rybkin, U. Ekström, and T. Helgaker,
    J. Comp. Chem. 34, 1842–1849 (2013)
    DOI: DOI: 10.1002/jcc.23327

  293. The accuracy of the Gaussian-and-finite-element-Coulomb (GFC) method for the evaluation of Coulomb integrals,
    M. Przybytek and T. Helgaker,
    J. Chem. Phys. 139, 054114 (2013)
    DOI: 10.1063/1.4817002

  294. Communication: Analytic gradients in the random-phase approximation,
    J. Rekkedal, S. Coriani, M. F. Iozzi, A. M. Teale, T. Helgaker, and T. B. Pedersen,
    J. Chem. Phys. 139, 081101 (2013)
    DOI: 10.1063/1.4819399

  295. Alternative separation of exchange and correlation energies in multi-configuration range-separated density-functional theory,
    A. Stoyanova, A. M. Teale, J. Toulouse, T. Helgaker, and E. Fromager,
    J. Chem. Phys. 139, 134113 (2013)
    DOI: 10.1063/1.4822135

  296. A theoretical study on proton conduction mechanism in BaZrO3 perovskite,
    T. Onishi and T. Helgaker,
    in Advances in quantum methods and applications in chemistry, physics, and biology,
    M. Hotokka, E. J. Brändas, J. Maruani, and G. Delgado-Barrio, eds.,
    Prog. T. Chem. 27, 233–248 (2013)
    DOI: 10.1007/978-3-319-01529-3_14

  297. 33S hyperfine interactions in H2S and SO2 and revision of the sulfur nuclear magnetic shielding scale,
    T. Helgaker, J. Gauss, G. Cazzoli, and C. Puzzarini,
    J. Chem. Phys. 139, 244308 (2013)
    DOI: 10.1063/1.4849177

    2014

  298. Non-perturbative calculation of molecular magnetic properties within current-density functional theory,
    E. I. Tellgren, A. M. Teale, J. W. Furness, K. K. Lange, U. Ekström, and T. Helgaker,
    J. Chem. Phys. 140, 034101 (2014)
    DOI: 10.1063/1.4861427

  299. Analytic cubic and quartic force fields using density-functional theory,
    M. Ringholm, D. Jonsson, R. Bast, B. Gao, A. J. Thorvaldsen, U. Ekström, T. Helgaker, and K. Ruud,
    J. Chem. Phys. 140, 034103 (2014)
    DOI: 10.1063/1.4861003

  300. Fermion N-representability for prescribed density and paramagnetic current density,
    E. I. Tellgren, S. Kvaal, and T. Helgaker,
    Phys. Rev. A 89, 012515 (2014)
    DOI: 10.1103/PhysRevA.89.012515

  301. Differentiable but exact formulation of density-functional theory,
    S. Kvaal, U. Ekström, A. M. Teale, and T. Helgaker,
    J. Chem. Phys. 140, 18A518 (2014)
    DOI: 10.1063/1.4867005

  302. The Dalton quantum chemistry program system,
    K. Aidas, C. Angeli, K. L. Bak, V. Bakken, R. Bast, L. Boman, O. Christiansen, R. Cimiraglia, S. Coriani, P. Dahle, E. K. Dalskov, U. Ekström, T. Enevoldsen, J. J. Eriksen, P. Ettenhuber, B. Fernández, L. Ferrighi, H. Fliegl, L. Frediani, K. Hald, A. Halkier, C. Hättig, H. Heiberg, T. Helgaker, A. C. Hennum, H. Hettema, E. Hjertenæs, S. Høst, I.-M. Høyvik, M. F. Iozzi, B. Jansík, H. J. Aa. Jensen, D. Jonsson, P. Jørgensen, J. Kauczor, S. Kirpekar, T. Kjærgaard, W. Klopper, S. Knecht, R. Kobayashi, H. Koch, J. Kongsted, A. Krapp, K. Kristensen, A. Ligabue, O. B. Lutnæs, J. I. Melo, K. V. Mikkelsen, R. H. Myhre, C. Neiss, C. B. Nielsen, P. Norman, J. Olsen, J. M. H. Olsen, A. Osted, M. J. Packer, F. Pawlowski, T. B. Pedersen, P. F. Provasi, S. Reine, Z. Rinkevicius, T. A. Ruden, K. Ruud, V. V. Rybkin, P. Sałek, C. C. M. Samson, A. Sánchez de Merás, T. Saue, S. P. A. Sauer, B. Schimmelpfennig, K. Sneskov, A. H. Steindal, K. O. Sylvester-Hvid, P. R. Taylor, A. M. Teale, E. I. Tellgren, D. P. Tew, A. J. Thorvaldsen, L. Thøgersen, O. Vahtras, M. A. Watson, D. J. D. Wilson, M. Ziolkowski, and Hans Ågren,
    WIREs Comput. Mol. Sci. 4, 269–284 (2014)
    DOI: 10.1002/wcms.1172

  303. Excitation energies along a range-separated adiabatic connection,
    E. Rebolini, J. Toulouse, A. M. Teale, T. Helgaker, and A. Savin,
    J. Chem. Phys. 141, 044123 (2014)
    DOI: 10.1063/1.4890652

  304. Charge-constrained auxiliary-density-matrix methods for the Hartree–Fock exchange contribution,
    P. Merlot, R. Izsák, A. Borgoo, T. Kjærgaard, T. Helgaker, and S. Reine,
    J. Chem. Phys. 141, 094104 (2014)
    DOI: 10.1063/1.4894267

  305. Mechanochemistry: the effect of dynamics,
    H. S. Smalø, V. V. Rybkin, W. Klopper, T. Helgaker, and E. Uggerud,
    J. Phys. Chem. A. 118, 7683–7694 (2014)
    DOI: /10.1021/jp504959z

    2015

  306. Geometry of the magic number H+(H2O)21 water cluster by proxy,
    M. J. Ryding, R. Izsák, P. Merlot, S. Reine, T. Helgaker, and E. Uggerud,
    Phys. Chem. Chem. Phys. 17, 5466–5473 (2015)
    DOI: /10.1039/c4cp05246c

  307. Use of density functional theory orbitals in the GVVPT2 variant of second-order multistate multireference perturbation theory,
    M. R. Hoffmann and T. Helgaker,
    J. Phys. Chem. A. 119, 1548–1553 (2015)
    DOI: /10.1021/jp507554v

  308. Calculating excitation energies by extrapolation along adiabatic connections,
    E. Rebolini, J. Toulouse, A. M. Teale, T. Helgaker, and A. Savin,
    Phys. Rev. A 91, 032519 (2015)
    DOI: 10.1103/PhysRevA.91.032519

  309. The importance of current contributions to shielding constants in density-functional theory,
    S. Reimann, U. Ekström, S. Stopkowicz, A. M. Teale, A. Borgoo, and T. Helgaker,
    Phys. Chem. Chem. Phys. 17, 18834–18842 (2015)
    DOI: 10.1039/c5cp02682b

  310. Special issue in honour of Nicholas C. Handy: Foreword,
    T. Helgaker, P. J. Knowles, T. J. Lee, J. E. Rice, and D. J. Tozer,
    Mol. Phys. 113, 1509–1510 (2015)
    DOI: 10.1080/00268976.2015.1047162

  311. Molecular properties in the Tamm–Dancoff approximation: indirect nuclear spin–spin coupling constants,
    C. Y. Cheng, M. S. Ryley, M. J. G. Peach, D. J. Tozer, T. Helgaker, and A. M. Teale,
    Mol. Phys. 113, 1937–1951 (2015)
    DOI: 10.1080/00268976.2015.1024182

  312. Excited states from range-separated density-functional perturbation theory,
    E. Rebolini, J. Toulouse, A. M. Teale, T. Helgaker, and A. Savin,
    Mol. Phys. 113, 1740–1749 (2015)
    DOI: 10.1080/00268976.2015.1011248

  313. FemEx—Female excellence in theoretical and computational chemistry: Editorial,
    B. Mennucci, O. Eisenstein, H. Fliegl, K. H. Hopmann, T. Helgaker, and K. Ruud,
    Int. J. Quantum Chem. 115, 1195–1196 (2015)
    DOI: 10.1002/qua.24961

  314. Coupled-cluster theory for atoms and molecules in strong magnetic fields,
    S. Stopkowicz, J. Gauss, K. K. Lange, E. I. Tellgren, and T. Helgaker,
    J. Chem. Phys. 143, 074110 (2015)
    DOI: 10.1063/1.4928056

  315. Current density-functional theory using meta-generalized gradient exchange–correlation functionals,
    J. W. Furness, J. Verbeke, E. I. Tellgren, S. Stopkowicz, U. Ekström, T. Helgaker, and A. M. Teale,
    J. Chem. Theory Comput. 11, 4169–4181 (2015)
    DOI: 10.1021/acs.jctc.5b00535

  316. Fractional Electron Loss in Approximate DFT and Hartree–Fock Theory,
    M. J. G. Peach, A. M. Teale, T. Helgaker, and D. J. Tozer,
    J. Chem. Theory Comput. 11, 5262–5268 (2015)
    DOI: 10.1021/acs.jctc.5b00804

  317. Ground-state densities from the Rayleigh–Ritz variation principle and from density-functional theory,
    S. Kvaal and T. Helgaker,
    J. Chem. Phys. 143, 184106 (2015)
    DOI: 10.1063/1.4934797

  318. Non-Born–Oppenheimer calculations of the HD molecule in a strong magnetic field,
    L. Adamowicz, E. I. Tellgren, and T. Helgaker,
    Chem. Phys. Lett. 639, 295–299 (2015)
    DOI: 10.1016/j.cplett.2015.09.051

  319. Excitation energies from ensemble DFT,
    A. Borgoo, A. M. Teale, and T. Helgaker,
    AIP Conf. Proc. 1702, 090049 (2015)
    DOI: 10.1063/1.4938857

    2016

  320. Alternative representations of the correlation energy in density-functional theory: A kinetic-energy based adiabatic connection,
    A. M. Teale, T. Helgaker, and A. Savin,
    J. Chin. Chem. Soc. 63, 121–128 (2016)
    DOI: 10.1002/jccs.201500132

  321. Foreword for special issue of Molecular Physics in honour of Andreas Savin,
    P. Gori-Giorgi, T. Helgaker, G. Scuseria, B. Silvi, and J. Toulouse,
    Mol. Phys. 114, 909–909 (2016)
    DOI: 10.1080/00268976.2016.1160647

  322. Electron localisation function in current-density-functional theory,
    J. W. Furness, U. Ekström, T. Helgaker, and A. M. Teale,
    Mol. Phys. 114, 1415–1422 (2016)
    DOI: 10.1080/00268976.2015.1133859

  323. Comparison of three efficient approximate exact-exchange algorithms: chain-of-spheres, pair-atomic resolution of the identity, and the auxiliary density matrix method,
    E. Rebolini, R. Izsák, S. S. Reine, T. Helgaker, and T. B. Pedersen,
    J. Chem. Theory Comput. 12, 3514–3522 (2016)
    DOI: 10.1021/acs.jctc.6b00074

  324. Calculation of NMR spin--spin coupling constants in strychnine,
    T. Helgaker, M. Jaszuński, and P. Świder
    J. Org. Chem. 81, 11496–11500 (2016)
    DOI: 10.1021/acs.joc.6b02157