Energy and Wave Functions of Interstitial Hydrogen in FCC and BCC Metals

Calculations have been performed of the energy and wave functions of H(D) atoms self-trapped on interstitial sites in fcc and bcc metals. The Schrödinger equation for a H(D) atom is solved in the field of interaction potential with surrounding metal atoms approximated by a sum of central pair potentials. Both ground and excited states have been studied for the purpose of making comparison with observed optical mode spectra of inelastic neutron scattering. It is shown from these calculations that a consistent understanding can be obtained of the excitation energy of a H atom on the T-site in V, Nb, Ta (bcc), the O-site in β-VH x (bct) and the O-site in Pd (fcc). Comparison of the calculated wave functions with Fourier-reconstructed density maps from neutron diffraction experiments is also made.