Molecular Dynamics Simulations of a Siloxane-Based Liquid Crystal Using an Improved Fast Multipole Algorithm Implementation

Abstract

AbstractIn our continuing efforts towards designing materials with controlled optical properties, largescale molecular dynamics simulations of a molecular cluster of a liquid crystalline cyclic siloxane are still limited by the size of the molecular system. Such simulations enable evaluation of the orientation order parameter of the system, as well as modelling the behavior of the material in bulk. This study summarizes improvements in the implementation of the fast multipole algorithm for computing electrostatic interactions which is included in the molecular dynamics program PMD[7, 8], such as the elimination of computations for empty cells and the use of optimal interaction lists. Moreover, an improved implementation of a 3-D Fast Multipole Method (FMM3D) based on the algorithm previously proposed[1, 2] is described in detail. The structure of the module, details of the expansions, parallelization, and its integration with the molecular dynamics simulation code are explained in detail. Finally, the utility of this approach in the study of liquid crystalline materials is briefly illustrated.