Molecular Dynamics Simulations Of Organic Molecular Systems Based On The Coarse-grained Model With Gay-Berne Potential And Point Electric Multipole Potential

In the polymer science fields the computer simulation technology has been rapid development. The computer simulation technology has been used in every field of the polymer physics and chemical. However, in the microscopic scales the polymer chain system model is still very difficult work, because of the current computer simulation computing power. Coarsening model can solve this problem well for some specific polymer system. This paper mainly introduced coarsening molecular dynamics simulation base on coarse grained potential and electricity for several multipole potential organic molecules system.Molecular dynamics simulation is a kind of technique of the movement of a single particle in large particle collection system, where the most key concepts is the movement. Namely, accurately record every the moment position and momentum of the particle with the time in the evolution of molecular dynamics. The particle of molecular dynamics can be atoms, molecules, or larger particles set. Then get the multi-body system static and dynamic characteristic with the statistical calculation method. Finally we can obtain the macroscopic System properties.Coarse graining of van der Waals potential is achieved by treating molecules as soft uniaxial ellipsoids interacting via a generalized anisotropic Gay-Berne function. The charge distribution is represented by point multipole expansion, including point charge, dipole, and quadrupole moments placed at the center of mass. The Gay-Berne and point multipole potentials are combined in the local reference frame defined by the inertial frame of the all-atom counterpart. The specific process is this, firstly builds the new force and selects many pairs of different molecular conformation. Secondly fits out the coarse-grained parameters and carries out the coarse-grained molecular dynamics of the two hundred molecular. Finally, analyses and compares the results of the whole atomic molecular dynamics simulation with the coarsening molecular dynamics simulation. Some fluid molecules have used this coarsening model for the molecular dynamics simulation. This model not only improves the calculation efficiency for several orders, but also makes the result reasonable consensus with the all atoms results and experimental data. We also have discussed the coarsening model for polarity molecular and molecular system.