GROUND-STATE STRUCTURES OF INTERMETALLIC COMPOUNDS - A 1ST-PRINCIPLES ISING-MODEL

Predictions of the equilibrium crystal structure of simple compounds, e.g., within first-principles total energy methods are usually carried out by searching for the lowest energy among a small number, O(10), of intuitively selected candidate structures. We show how calculations of the total energies of O(10) structures can be used instead to define a first-principles, multi-spin Ising Hamiltonian, whose ground state structures on a fixed lattice can be systematically searched using lattice theory methods. This is illustrated for the intermetallic compounds CuAu, CuPd, CuPt, and CuRh, for which the correct ground states are identified out of more than 65,000 possible structures.