Abstract
Describing intermolecular forces is fundamental to modeling and predicting the behavior of molecular systems. In particular, long-range molecular interactions with electrostatic, induction, and dispersion as the main components play a critical role, especially for low-temperature and low-density regimes. Long-range interactions are often described through perturbation theory, representing the electronic charge distribution via a multipolar series of the moments and polarizability tensors corresponding to each molecule. However, while the theory is well established, obtaining the resulting analytical expressions (and their practical implementation) constitutes a highly complex and system-dependent task. To address this challenge, we developed long-range-fit (LRF), an interactive and user-friendly software package designed to automate the generation and fitting of long-range interaction terms for arbitrary molecules in nondegenerate (ground or excited) electronic states. We have derived and implemented all terms up to 15th order, without approximations, via a spherical tensor representation, with symmetry adaptation to all molecular point-group symmetries. The resulting potential energy surface is compatible with most representations of the close interaction region.
Recommended Citation
A. L. Batista-Planas et al., "Long-Range Fit: A Software Package for the Representation and Study of Long-Range Molecular Interactions," Journal of Chemical Theory and Computation, vol. 22, no. 3, pp. 1363 - 1380, American Chemical Society, Feb 2026.
The definitive version is available at https://doi.org/10.1021/acs.jctc.5c01984
Department(s)
Chemistry
Publication Status
Open Access
International Standard Serial Number (ISSN)
1549-9626
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2026 American Chemical Society, All rights reserved.
Publication Date
10 Feb 2026
PubMed ID
41591892
