THE PHASE BEHAVIOR OF 5CB LIQUID CRYSTALLINE SYSTEM STUDIED BY COARSE-GRAINED MD SIMULATIONS

摘要

@@It is well known that the current molecular dynamics (MD) simulation is inaccessible to the large-size system. But the coarse-grained MD simulation can overcome this shortcoming due to the reduation in the degrees of freedom during the coarse-grained process. 5CB has been widely used in materials, such as liquid-crystalline gels', thin films2, and liquid display materials3. For SCB molecule, three different coarse-grained models, which are 5P, 6P, 7P models depending on the CG sites in single 5CB molecule, have been developed. To get a reasonable force field, we separate the non-bonded interaction potentials from the intramolecular bonded interaction potentials. The intramolecular force field is obtained by Boltzmann inversion method based on the distributions of bonds and angles from atomistic simulations. While the intermolecular interaction potential is modelled by a softer analytical function-Lennard Jones 9-6 form potential in which force parameters are optimized in order to reproduce the densities as well as the radial distribution functions from atomistic simulations.