Molecular Dynamics Simulation of Organic Solvents Based on the Coarse-Grained Model

Abstract

To obtain Gay-Berne (GB) parameters, we carried out Monte Carlo sampling of four reference configurations based on the Boltzmann distribution. After comparing with the van der Waals potential within the all-atom model we obtained the GB parameters. Also by fitting the charge, dipole, and quadrupole with the electric potential obtained from quantum chemical computations with Gaussian 03 we obtained the electric multipole potential (EMP) parameters. With the GB-EMP parameters we then carried out molecular dynamics simulations (MDS) for CHCl3 and tetrahydrofuran (THF) based on the coarse-grained (CG) model. Compared with the all-atom model, the CG model can reproduce the simulation results on the whole, but there are some deviations in the simulations in some details. The reason is that we only take one interaction site into account in this work. Therefore, for more complicated molecules it is necessary to take the placement of the interaction sites into account. Additionally, the multi-sites situation is also considered in the MDS within the frame of the coarse-grained model.