Coherent-potential-approximation calculations forPdHx

The angular-momentum components of the density of states (DOS) for substoichiometric $\mathrm{Pd}{\mathrm{H}}_x$ were calculated by the coherent-potential approximation (CPA). A tight-binding form of the CPA was used, based on a Slater-Koster fit to first-principles APW calculations. The CPA DOS's have been used to calculate the electron-phonon interaction and superconducting transition temperatures as a function of hydrogen concentration $x$. The results are in good agreement with experiment and with previous calculations in which the rigid-band model was utilized. The CPA results for the electronic-specific-heat coefficient as a function of $x$ are in excellent agreement with experiment while the results of the rigid-band model are not.