On a Deformation-Driven Continuum-Related Parrinello-Rahman Molecular Dynamics

Investigations into the atomistic-to-continuum coupling are recently pursued in literature. A hierarchical modelling in terms of a macroscale treated by continuum mechanics and the microscale governed by statistical mechanics may be a very fruitful combination. If the microscale is simulated with the help of molecular dynamics, the isostress-isoenthalpic ensemble as proposed by Parrinello and Rahman presents a beneficial choice. This statistical ensemble is remarkable as the equations of motion are derived from a Lagrangian. Recently, this Lagrangian was situated into a continuum mechanics setting. This paper investigates the behavior of this continuum-related Lagrangian in a kinetics-driven setting (by imposing an external stress) and a kinematics-driven setting (by imposing the shape of the molecular dynamics cell) in terms of a numerical example. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)