Molecular dynamics simulation of the liquid-vapor interface: Binary mixtures of Lennard-Jones fluids

We have performed molecular dynamics simulations to study structure and equ ilibrium properties of liquid-vapor interfaces of binary mixtures containin g argon and methane over the entire range of compositions. The phase equili brium data obtained from our simulations are compared with those from NpTtest particle calculations of an analogous system. Values of the surface te nsion were computed and extrapolated to the full Lennard-Jones potential us ing a new ansatz to determine tail contributions to the surface tension dir ectly within the simulation run. This new method uses the actual partial de nsity profiles obtained within the simulation and, therefore, does not requ ire any prescribed functional form. From both the surface tension results a nd the partial density profiles the relative enrichment of argon at the int erface was estimated. (C) 1999 American Institute of Physics. [S0021-9606(9 9)53401-6].