A superposition model of metal-hydrogen interaction in intermetallic compound hydrides

A model in which the metal-hydrogen interatomic interaction potential in th e solid phase is described by the Gauss normal distribution function was su ggested to explain and predict equilibrium isotopic effects in hydrogen-int ermetallic compound hydride systems. The quantum mechanical variational pri nciple was used to parametrize the Gauss potentials for Group IV and V tran sition metals in the approximation of local modes for hydrogen atom vibrati ons. These potentials were transferred to intermetallic compounds with Lave s phase structures. Calculations performed in a similar way gave the temper ature dependences of separation coefficients for hydrogen isotopes that wer e close to experimental for both stoichiometric and superstoichiometric for ms of AB(2) compounds. These results prove the applicability of the represe ntation of the potential for hydrogen in intermetallic compounds as a super position of the potentials of separate metal atoms, which allows simple cri teria for the search for systems with the largest isotopic effect to be for mulated and substantiated.