Long-range contributions for the use of truncated pair potentials of molecular systems - application to nitrogen N2

• Published in: Molecular physics Vol. 113; no. 13-14; pp. 1585 - 1589
• Main Authors: Senn, F., Wiebke, J., Schwerdtfeger, P., Pahl, E.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 18-07-2015; Taylor & Francis Ltd
• Subjects: importance of Monte Carlo environments; long-range correction integral; Monte Carlo simulation; Nitrogen; truncated pair potential
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268976.2014.994568

An accurate and efficient evaluation of configuration energies of many-particle clusters or cells is a crucial ingredient in all molecular simulations. Usually, these energies are computed by summing over all pairwise interactions for which the distance of the particles' barycentres lie within a chosen cut-off sphere. Here, we present a new method to approximate the missing long-range contributions within an importance sampling Monte Carlo scheme. For the sampling of the configurations, an overlap sampling protocol is used to ensure that the sampling space is appropriate for the integrand of the reference system as well. Configurations outside the integration domain (i.e. inside the cut-off sphere) are discarded while detailed balance is (mostly) preserved. The method is shown to work for simple model potentials where the exact solutions of the long-range contribution integrals are known. A first application to solid, liquid and gas-like configurations with about 3500 nitrogen molecules yields promising results.