ELECTRON-STRUCTURE AND ACTIVATION-ENERGY OF HYDROGEN IN ALPHA-ZR USING NONLINEAR RESPONSE THEORY

The electron structure of hydrogen in hcp Zr is calculated by using se lf-consistent nonlinear screening theory. The host-ion contribution is included through the spherical solid model potential (SSMP). The resu lting charge density and scattering phase shifts are used to calculate the activation energy and residual resistivity of hydrogen in alpha-Z r matrix. The calculated activation energy 0 . 285 eV is found in reas onably good agreement with experimental value 0 . 3 eV. The estimated residual resistivity 0 . 53 mu Omega cm/at% for Zr-H system using the scattering phase shifts agrees reasonably well with the observed value 0 . 27 mu Omega cm/at%. The calculated configurational energy shows t hat hydrogen prefers tetrahedral(T)-sites over octahedral(O)-sites in alpha-Zr. The strong binding energy of electron-proton suggests that h ydrogen forms zirconium hydride.