Improved Description of Sulfur Charge Anisotropy in OPLS Force Fields: Model Development and Parameterization.

ABSTRACT: The atomic point-charge model used in most molecular mechanics force fields does not represent well the electronic anisotropy that is featured in many directional noncovalent interactions. Sulfur participates in several types of such interactions with its lone pairs and σ-holes. The current study develops a new model, via the addition of off-atom charged sites, for a variety of sulfur compounds in the OPLS-AA and OPLS/CM5 force fields to address the lack of charge anisotropy. Parameter optimization is carried out to reproduce liquid-state properties, torsional and noncovalent energetics from reliable quantum mechanical calculations, and electrostatic potentials. Significant improvements are obtained for computed free energies of hydration, reducing the mean unsigned errors from ca. 1.4 to

SUBMITTER: Yan XC 

PROVIDER: S-EPMC5816952 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature