Early dynamics of the potential energy evolution in two-dimensional gas-liquid phase separation

Molecular dynamics simulations have been performed to investigate the early -time dynamic behaviour of gas-liquid phase separation in two dimensions by using the evolution of the potential energy. It is found that the average potential energy per particle u(t) shows a good linear relationship with th e average number of nearest-neighbour particles n(nn) (t) after a brief tim e. The results also show that u(t) follows a positive power law in time in the early stage of phase separation. The excess energy per particle u(t) - u(infinity) proportional to t(-1/2) is also confirmed in the late stage. Th ese results suggest that u (t) may be considered as a parameter describing the entire phase separation process in gas-liquid systems.