Constant pressure molecular dynamics simulations for ellipsoidal, cylindrical and cuboidal nano-objects based on inertia tensor information

Abstract

We present an extension to a constant-pressure molecular dynamics method for ellipsoidal finite systems that allows one to deal with nano-objects of cylindrical and cuboidal shapes. The method is based on the inclusion of a pressure x volume term in the system Lagrangian, where the volume is defined as a function of the eigenvalues of the inertia tensor. We illustrate how such a method works for selected systems, including CdSe nanocrystals and nanorods, carbon nanotubes and NaCl nanocrystals over a range of pressures. We also assess its performance in comparison with the use of an auxiliary pressure transmitting medium.