An effective temperature approach for molecular dynamics simulations of quantum solids

We examine two standard methods to incorporate quantum effects in classical molecular dynamics simulations of quantum solids. It is shown that thermal harmonic quantum correction fails to generate a reliable structure of solid neon, while augmenting the classical equations of motion with a quantum Langevin force is no longer appropriate for heavier noble gases. An alternative approach is proposed which accounts as simply as possible for the characteristic frequency and the anharmonicity of lattice vibrations. Simulations carried out within this approach in the canonical ensemble show that normal solid-like structure could be achieved while lattice symmetry is preserved. (c) 2006 Elsevier B.V. All rights reserved.