An equilibrium Monte Carlo simulation capable of treating super-abundant vacancy formation and ordering in metal-H systems was developed. It combines lattice site occupations and continuous degrees of freedom which enables one to perform insertion/removal moves and H-vacancy cluster moves while the position of the particles were sampled. The bulk phase diagram in (µM,NH,V,T) ensemble was estimated for concentrations lower than 1at%. Within the framework of an EAM Al-H potential, ordering of superabundant vacancies in the shape of chains and platelets was reported at room temperature.

Superabundant Vacancies in a Metal-Hydrogen System - Monte Carlo Simulations. D.Tanguy, M.Mareschal: Physical Review B, 2005, 72[17], 174116 (13pp)