Development of Optimized Potentials for Liquid Simulation (OPLS) Force Field to Sulfur Mustard in Order to Study its Adsorption on Graphene

In this study, the OPLS all-atom model was developed for sulfur mustard in order to study the adsorption of this compound on graphene. Intramolecular bonding parameters and Lennard?Jones nonbonding parameters are taken from the OPLS all-atom force field database. Partial charges are determined by ab initio calculations at HF/6-31g(d) level. The results showed that the OPLS all-atom force field predicts the physical properties of sulfur mustard like density and heat of evaporation with the mean error of less than 1% and 5% respectively at temperatures of 298 K and 293 K compared to experimental data. The comparison of intramolecular bonding parameters obtained from molecular dynamics simulation and quantum mechanical calculations showed that these results are well consistent with each other. Also, the study of the interaction energy between sulfur mustard and graphene by molecular mechanics and quantum mechanics on coronene as a model of graphene indicated that OPLS force field can be used as an accurate and reliable model in the molecular dynamics simulation studies of this compound on the adsorbents based on graphene.