A method is developed to take into account the contribution of the Umklapprozesse to the electron-phonon interaction in polyvalent metals. This method is used to compute—from first principles—the high-temperature resistivity of non-transition metals as well as the transition temperature Tc of non-transition superconductors along the lines of
,
and
's theory of superconductivity (Phys. Rev.108, 1175 (1957)). The effect of pressure on Tc is also computed and its dependence upon the band structure is stressed.