Small-polaronic diffusion of light interstitials in bcc metals

The small-polaronic diffusion associated with simple models of light interstitials in bcc metals has been investigated. By transcending the simplifications which are often introduced in studying electronic small-polaron transport, we calculate diffusion coefficients which are reasonably consistent with available data. In particular, an explanation of the "anamalous" isotope dependence observed for hydrogen diffusion in bcc metals emerges from these studies.