Abstract
Phonon-limited resistivities for Li and Na have been calculated for both FCC and BCC structures using first-principle pseudopotentials. The calculated values of rho show a strong structural dependence, especially at low temperature. An important contribution to this dependence comes from a structure-related difference in the conditions controlling the onset of Umklapp scattering. For Na it is possible to measure rho in both BCC and closepacked phases and the authors' results agree well with these experiments.