A new method for the molecular dynamics simulation of hard core molecules

A new method for the dynamical simulation of a hard core fluid is introduced. The method differs from the traditional Alder–Wainwright algorithm in that the effects of collisions are obtained in response to observed core overlaps. The method is in principle more approximate than that of Alder and Wainwright, but extensive tests on a system of 72 hard disks do not show any measurable inaccuracy in the equation of state, the pair correlation function or the velocity autocorrelation function in this system. The principle advantage of the new method is that it is readily extended to potentials with a hard core and an attractive tail. Preliminary calculations on several fluids with a hard core and an attractive tail suggest that some dynamical properties may be unexpectedly sensitive to the detailed form of the attractive part of the intermolecular potential.