Semigrand-canonical ensemble simulations of the phase diagrams of alloys

We show how Monte Carlo simulations with the explicit interchange of atoms and the use of the semigrand-canonical ensemble, can be used to calculate phase diagrams for alloys. We illustrate our approach with the system Pd/Rh using the embedded atom method with potential parameters derived from ab initio density functional calculations. Our techniques take full account of local structural distortion, clustering and thermal effects.