Domain decomposition of the two-temperature model in DL_POLY_4

ABSTRACT

Including the effects of excited electrons in classical simulations, at the level of the two-temperature model, involves the coupling of a grid-based finite-difference solver for a heat diffusion equation and classical molecular dynamics simulations with an inhomogeneous thermostat. Simulation of large systems requires domain decomposition of both particle-based and grid-based techniques. Starting with the CCP5 flagship code DL_POLY_4 as the domain-decomposed molecular dynamics code, we devised a method to divide up temperature grids among processor cores in a similar fashion, including the appropriate communications between cores to deal with boundaries between grid divisions. This article gives the outline of how the domain decomposition of the temperature grids was achieved, as well as some example applications of the two-temperature model implementation in DL_POLY_4.

KEYWORDS:

• DL_POLY
• domain decomposition
• molecular dynamics
• two-temperature model
• finite difference method

Acknowledgments

MAS and ITT would like to thank Eva Zarkadoula (now at Oak Ridge National Laboratory) for extensive beta testing of DL_POLY_4 with the domain-decomposed two-temperature model.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Funding by Engineering and Physical Sciences Research Council (EPSRC) (EP/I029354/1) for the code development work outlined in this article is gratefully acknowledged.