The London program was conceived by:

At the time, both worked at CTCC, University of Oslo. The specific ideas and mathematical derivations leading to London grew out of discussions between Erik Tellgren and Alessandro Soncini about crystalline materials subject to finite magnetic fields. The focus changed during the course of the theoretical work to molecules in finite magnetic fields. These themes coincided with research interests of Trygve Helgaker. The programming for the first version of London, consisting of an integral-evaluation library for hybrid basis sets and functionality for Hartree-Fock wave function optimization, was done by Erik Tellgren. The program was written from scratch as a completely self-contained C++ program, save for the reliance on the lapack library for basic linear algebra functionality. The name 'London' was chosen in honor of the physicist Fritz London, after whom London orbitals are also named.

Another important role has been played by:

Trygve Helgaker has been a key person by developing and leading research projects related to London, and supporting its continued, long-term development in his group.


Over time, several developers have joined the London team and made important programming contributions. Roughly in chronological order:

Citation policy

All relevant journal articles describing implemented functionality in London should be cited. For example, the first article [JCP 129:154114] describes the implementation of the integral-evaluation library. As London relies on the XCFun package by U. Ekström for implementations of specific DFT functionals, this package should be cited when relevant. Additionally, the program itself can be cited as:

LONDON, a quantum-chemistry program for plane-wave/GTO hybrid basis sets and finite magnetic field calculations. By E. Tellgren (primary author), T. Helgaker, A. Soncini, K. K. Lange, A. M. Teale, U. Ekström, S. Stopkowicz, J. H. Austad, and S. Sen. See for more information.