An effective force field for molecular dynamics simulations of dimethyl sulfone

Abstract

A rigid five-site united atom model for dimethyl sulfone (DMSO₂) compatible with the GROMOS force field is parametrized and tested. The parameters were optimized with respect to experimental quantities such as liquid density, heat of vaporization, shear viscosity and excess free energy. Good agreement with pure component properties is achieved except for the static dielectric permittivity which is calculated too low. Together with the SPC model for water the new DMSO₂ model was used to study aqueous mixtures at low concentrations and compared to aqueous mixtures of DMSO. It is concluded that interaction parameters for sulfoxide oxygen are not directly transferable to sulfonyl oxygen.

Keywords:

• molecular dynamics
• liquid model
• force field
• dimethyl sulfone

Acknowledgments

The authors thank Bruno A.C. Horta and Sereina Riniker for fruitful discussions. This work was financially supported by the National Center of Competence in Research (NCCR) in Structural Biology and by grant number 200020-121913 of the Swiss National Science Foundation, and by grant number 228076 of the European Research Council, which is gratefully acknowledged.