KONDO-LATTICE-LIKE EFFECTS OF HYDROGEN IN TRANSITION-METALS

We discuss the possibility of a Kondo-like effect associated with H in metals, resulting from the strong dependence of the H 1s orbital radi us on the occupation number. We demonstrate that such a strong breathi ng property of the orbital radius, which translates directly into a st rong occupation-dependent hopping, results in the formation of local s ingletlike bound states involving one electron on H and one on the sur rounding metal orbitals. We also show that already at a mean-field lev el an occupation-dependent hopping integral leads to a substantial pot ential-energy Correction on hydrogen, and that the failure of band-str ucture methods to incorporate this correction is responsible for the i ncorrect prediction of a metallic ground state for the YH3 switchable mirror compounds. [S0163-1829(97)06739-8].