Isobaric molecular dynamics simulations of hard sphere systems - art. no. 061106

We describe an implementation of the Andersen algorithm for simulating the molecular dynamics in the isobaric isoenthalpic (NPH) ensemble for the hard sphere potential. The work is based on the adaptation of the Andersen algo rithm to hard spheres by de Smedt et al. For a hard sphere system in the NP H ensemble, the particle velocities are not constant between collisions and we describe an efficient method for handling this part of the dynamics. Th e method is extended to give an NPT ensemble simulation of hard sphere syst ems by applying an ad hoc rescaling of the velocities. The accuracy of the algorithms is tested by comparison with traditional NVE simulation results for the structural, thermodynamic, and transport properties.