Use of Computer Experiments to Locate the Melting Transition and Calculate the Entropy in the Solid Phase

Modern computers can accurately simulate the behavior of idealized systems of several hundred particles, but they have trouble in studying the melting process in which small-system surface effects make the transition irreversible. It is here suggested that a thermodynamically reversible path linking the solid and fluid phases can be obtained by using a periodic ``external field'' to stabilize the solid phase at low density. The properties of the artificially stabilized solid at low density are studied theoretically, and two practical schemes are outlined for determining the melting parameters by using computer-calculated entropies.