Million-atom molecular dynamics simulation by order-N electronic structure theory and parallel computation

TL;DR

This paper presents a highly efficient parallel order-N electronic structure method for large-scale molecular dynamics simulations, enabling million-atom simulations with high accuracy and near-perfect parallel efficiency.

Contribution

The authors develop and demonstrate a parallel order-N electronic structure method using Wannier states, achieving efficient million-atom molecular dynamics simulations.

Findings

Parallelism efficiency of 98.8% achieved

Simulation of 2 million atoms in 3 minutes on 64 processors

Results agree within 2-10% of exact diagonalization

Abstract

Parallelism of tight-binding molecular dynamics simulations is presented by means of the order-N electronic structure theory with the Wannier states, recently developed (J. Phys. Soc. Jpn. 69,3773 (2000)). An application is tested for silicon nanocrystals of more than millions atoms with the transferable tight-binding Hamiltonian. The efficiency of parallelism is perfect, 98.8 %, and the method is the most suitable to parallel computation. The elapse time for a system of $2\times 10^6$ atoms is 3.0 minutes by a computer system of 64 processors of SGI Origin 3800. The calculated results are in good agreement with the results of the exact diagonalization, with an error of 2 % for the lattice constant and errors less than 10 % for elastic constants.