A new order parameter for tetrahedral configurations

Abstract

A new order parameter, S, is introduced to test for tetrahedral configurations. It is applied to analyse the results of three simulations: (1) molecular dynamics simulation of ice Ih (hexagonal ice) at 200 K, using the SPC/E water potential; (2) Monte Carlo simulation of aqueous solution of methane, using the OPLS methane potential and the TIP4P water potential; and (3) Monte Carlo simulation of Lennard-Jones spheres. The quasi-tetrahedral configurations of water molecules in different states can be adequately described using S.