Argon force field revisited: a molecular dynamic study

We report the improvement of five argon force fields by scaling Lennard-Jones 6-12 potential (LJP) energy (epsilon) and distance (sigma) parameters to reproduce liquid-vapor phase diagram and surface tension simultaneously, with molecular dynamics. Original force fields reproduce only liquid-vapor phase diagram among other properties except surface tension. Results showed that all new force fields obtained by scaling LJP parameters reproduce well the experimental surface tension and the liquid-vapor phase diagram, also the LJP energy and distance parameters converge in a nearby region in the epsilon-sigma phase space, which is different from the original values. This study gives the intervals where the numerical values of epsilon and sigma reproduce both properties mentioned above. Furthermore, a study to calculate surface tension to avoid finite size effects is shown.