Molecular dynamics with anisotropic site potentials: butane

Abstract

Molecular dynamics simulations of liquid butane have been performed using four different alkane potentials that are available in the literature. One of these, the four-anisotropic-site potential of Price, was designed to mimic the behaviour of a full atom-atom potential (i.e. 14 isotropic sites per molecule). The anisotropic site model reproduced a range of thermodynamic, structural and dynamic properties of the 14-site model very well, and did so in only half the computer time. In contrast, there were significant variations among the predictions of the other three potentials. It was concluded that anisotropic site potentials are at least as flexible as full atom-atom representations, and that they offer significant computational savings.