Discretization errors in molecular dynamics simulations with deterministic and stochastic thermostats

[摘要] We investigate the influence of numerical discretization errors on computed averages in a molecular dynamics simulation of TIP4P liquid water at 300 K coupled to different deterministic (Nose-Hoover and Nose-Poincare) and stochastic (Langevin) thermostats. We propose a couple of simple practical approaches to estimating such errors and taking them into account when computing the averages. We show that it is possible to obtain accurate measurements of various system quantities using step sizes of up to 70% of the stability threshold of the integrator, which for the system of TIP4P liquid water at 300 K corresponds to the step size of about 7 fs. (C) 2010 Elsevier Inc. All rights reserved.

[发布日期] 2010-12-10

[关键词] Numerical integrator;Configurational temperature;Diffusion coefficient;Debye relaxation time;Radial distribution function;Nose-Hoover thermostat;Langevin thermostat;Backward error analysis;Richardson extrapolation