PNNL

Abstract

We report classical molecular dynamics simulations of liquid water with a flexible, polarizable, Thole-type interaction potential. We report the radial distribution functions, average energy, internal geometry and dipole moment in the liquid as well as the density, dielectric constant and self-diffusion coefficient at T=300 K from (NVT) and (NPT) classical molecular dynamics simulations. In order to facilitate these simulations we have found it necessary to modify the original version of the TTM2-F potential [J. Chem. Phys. 116, 5115 (2002)] in order to consistently describe the fragment molecular dipole moment and alleviate problems arising at small intermolecular separations. Furthermore, the parallel implementation of the revised version (TTM2.1-F) under periodic boundary conditions enables for the efficient calculation of the macroscopic structural and thermodynamic properties of liquid water as its performance scales superlinearly with number of processors for a 256 molecule periodic simulation box.