THEORETICAL-STUDIES OF THE HIGH-PRESSURE PHASES IN CERIUM

We present full potential linear-muffin-tin-orbital calculations based on the local-density approximation, which reproduce the T = 0 phase diagram of cerium (Ce), including the volumes and transition pressures for both the a --> a', and the a' --> bct transitions. The a --> a' transition is largely determined by a balance of two competing terms: a Madelung term and a 4f one-electron term. The a' --> bct transition is driven by both 4f and 5d partial-wave contributions. This is the first successful, ab initio calculation of a crystallographic (T = 0) phase diagram of an f-electron system.