Abstract
Molecular dynamics (MD) is one of the computer simulation methods to observe the microscopic state of materials. It was reported that the diffusion coefficient, which is obtained from MD simulation, increased with the increasing of the system size for 128-2,048 water molecules and 128-1,000 Lennard-Jones (LJ) particles fluid. We have performed the large scale MD simulations to study for the system size effect on the diffusion coefficient. The number of molecules for LJ is 1,000-100,000, and for water is 1,000-50,000. MDGRAPE-3, which is the special purpose computer for molecular dynamics simulations, has been employed for water simulation. A crossover from the system-size-dependent to the system-size-independent effects is observed for both LJ and water.
