OpenFCI Home Page
Blurry image of a wave function


OpenFCI is an open source library for doing full configuration-interaction calculations on quantum dots in two dimensions. It is not limited to this application, however, as the core library functions constitute generic functionality for almost any many-body calculation using occupation number formalism.

OpenFCI is released in the Gnu General Public License, and is primarily indended as a research tool. It may of course also be useful in educational settings, since doing simple many-body computations with OpenFCI is as easy as it gets.

A paper has been written, documenting the methods and concepts used in OpenFCI (arXiv:0810.2644). The interested should consult this paper and other sources on many-body quantum physics — see "suggested reading" further down the page.

System requirements

OpenFCI is intended to be platform-independent, but is developed on Ubuntu Linux 7.04 using Gnu C++ 4.2.1, in addition to BLAS, LAPACK and ARPACK (version 0.5 uses arpack++ as well; later versions don't) libraries for linear algebra computations. So, one must be able obtain versions for these libraries for the desired platform.

Exactly what version of Gnu C++ one needs, or exactly what other C++ compilers will work, I cannot say. I will probably perform tests with (for example) the Intel C++ compiler on both Windows and Linux. I have not delibrately used any compiler-specific features, though.

One also needs Gnu automake and related programs. For Windows, I recommend MinGW and msys, see

Download and installation instructions

  1. Download openfci-0.6.tar.gz.
  2. Untar the archive at a suitable place. Read README for details and things omitted in this short description.
  3. Make sure BLAS, LAPACK and ARPACK (and arpack++ for version 0.5) are properly installed.
  4. Run './configure'. This will check your system for compatibility.
  5. If successful, run 'make'. This will build the library and the executables.
  6. Run 'make install' to install the whole thing at a proper place.
  7. If you want a copy of the documentation, run 'doxygen' and save the contents of the 'doc' subdirectory where you wish.


The code is thoroughly commented using Doxygen-compatible comments. The resulting documentation is also available online here. Alternatively, download the documentation as a tar.gz file, openfci-0.5-doc.tar.gz.

Suggested reading

  • Kvaal, S: Open source FCI code for quantum dots and effective interactions, arXiv:0810.2644
  • Kvaal, S: Harmonic oscillator eigenfunction expansions, quantum dots, and effective interactions, (2008) arXiv:0808.2145
  • Reimann, S. & Manninen, M: Electronic structure of quantum dots, Rev. Mod. Phys. 74 (2002) pp.1283–1342
  • Raimes, S: Many-electron theory, (1973) North-Holland publishing company