Issue
EPL
Volume 88, Number 2, October 2009
Article Number 20001
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/88/20001
Published online 27 October 2009
EPL, 88 (2009) 20001
DOI: 10.1209/0295-5075/88/20001

Large-scale efficient Langevin dynamics, and why it works

Jiayu Dai and Jianmin Yuan

Department of Physics, National University of Defense Technology - Changsha 410073, PRC

jmyuan@nudt.edu.cn

received 9 July 2009; accepted in final form 30 September 2009; published October 2009
published online 27 October 2009

Abstract
An effective method with large convergence tolerance for self-consistent-field calculations is proposed to accelerate Born-Oppenheimer molecular-dynamics simulations based on the density functional theory. The errors for forces with large convergence tolerance are taken as the noises of Langevin dynamics for constant-temperature molecular dynamics. We use different systems such as crystalline Si, liquid Si and liquid water to verify the accuracy and efficiency of the method. Results of the new method are consistent with those of sufficiently accurate methods and the dynamical properties of the systems are reproduced as well. The efficiency of computation is improved by a factor of two to three using this model. Our analysis provides three reasons which explain why the method works. This development effectively extends the application of Born-Oppenheimer molecular dynamics to larger systems.

PACS
02.70.Ns - Molecular dynamics and particle methods.
71.15.-m - Methods of electronic structure calculations.
05.10.Gg - Stochastic analysis methods (Fokker-Planck, Langevin, etc.).

© EPLA 2009