Evaluation of the excess free energy for two-center-Lennard-Jones liquids using the bent effective acceptance ratio

A method of calculating the excess Helmholtz free energy from the average o f the bent effective acceptance ratio for two-center-Lennard-Jones liquids has been presented. The bent effective acceptance ratio has been newly comp osed from the acceptance ratio for the potential energy difference between a configuration in the Metropolis Monte Carlo procedure and random virtual configuration generated by the separate parallel Monte Carlo procedure and the Boltzmann factor for half the potential energy difference. The excess H elmholtz free energy was calculated directly from the average of the bent e ffective acceptance ratio through a single Metropolis Monte Carlo run. Beca use the separate parallel Monte Carlo procedure was used, this method can b e applied to molecular dynamics simulations. For two-center-Lennard-Jones l iquids, the average of the bent effective acceptance ratio gave better resu lts than use of the modified effective acceptance ratio in the previous wor k.