PHASE-DIAGRAM OF A LENNARD-JONES SOLID

A phase diagram of a Lennard-Jones solid at kT/epsilon greater-than-or -equal-to 0.8 is constructed by our recent perturbation theory. It sho ws the stability of the face-centered-cubic phase except within a smal l pressure and temperature domain, where the hexagonal-close packed ph ase may occur. The theory predicts anharmonic contributions to the Hel mholtz free energy (important to the crystal stability) in good agreem ent with Monte Carlo data.