Second virial coefficients: a route to combining rules?

• Published in: Molecular physics Vol. 115; no. 9-12; pp. 1191 - 1199
• Main Authors: Rouha, Michael, Nezbeda, Ivo
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 18-06-2017; Taylor & Francis Ltd
• Subjects: Alkanes; combining rules; corresponding-state scaling; Lennard-Jones potential; Lorentz-Berthelot rule; n-alkane mixtures; Scaling; Second virial coefficient; site-site interactions; TraPPE force field; Virial coefficients
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268976.2016.1263763

The effect of combining rules on the second virial coefficient is systematically examined for a series of n-alkanes up to octane with the aim to assess the impact of the individual site-site interactions and to find potential general regularities. To describe the interactions of n-alkanes, we use the TraPPE-UA force field and examine the effect of deviations from the Lorentz-Berthelot combining rule, both separately for the energy and length scaling parameters of the Lennard-Jones potential, and for their combined change. The results reveal the different impacts of both site-site interactions and distance and energy scaling parameters on the cross virial coefficient, which can potentially be used in force field development. An attempt is also made to find a scaling that could provide a uniform result.