Interactions between interstitial H atoms and interstitial O atoms in crystalline material were analyzed by applying a parameter-free Hartree-Fock method to clusters which contained 5, 26 or 35 host atoms. It was found that no configurations with significant O-H bonding were energetically favorable, and that the activation energy for the diffusion of interstitial O was considerably lower when H was present than when it was not. It was deduced that H enhanced the diffusivity of interstitial O by several orders of magnitude.

S.K.Estreicher: Physical Review B, 1990, 41[14], 9886-91