IMPLICIT FINITE-SIZE EFFECTS IN COMPUTER-SIMULATIONS

The influence of periodic boundary conditions (implicit finite-size ef fects) on the anisotropy of pair correlations in computer simulations is studied for a dense classical fluid of pair-wise interacting krypto n atoms near the triple point. Molecular dynamics simulation data for the pair distribution function g(N)(r) = g(N)(r, theta, phi) of N-part icle systems, as a function of radial distance r, polar angle theta, a nd azimuthal angle phi, are compared directly with corresponding theor etical predictions [L. R. Pratt and S. W. Haan, J. Chem. Phys. 74, 186 4 (1981)]. For relatively small systems of N = 60, 80, and 108 atoms, significant angular variation is observed, which is qualitatively, and in several cases quantitatively, well predicted by theory. Finite-siz e corrections to the spherically-averaged radial distribution function g(N)(r), however, are found to be comparable to random statistical er rors for runs of 10(5) time steps.