MANY-ATOM SCREENING EFFECTS ON DIFFUSION IN DENSE HELIUM

The structure and dynamics of helium at 5 eV over the density range 1.5 less-than-or-equal-to rho less-than-or-equal-to 8 g/cm3 were studied using self-consistent-field molecular dynamics. Representative results for the pair-correlation function, velocity autocorrelation function, and the average charge density surrounding an atom are presented. Many-atom screening is found to have an important effect on all of these quantities above 0.3 g/cm3. Above 2 g/cm3, screening effects appear to saturate, and the coefficient of diffusion tends to the limit of a one-component plasma.