Validity of the Boltzmann Equation for Systems with Both Electron-Phonon and Impurity Scattering

Abstract
A recent calculation of Mills indicating large deviations from Mathiessen's rule is shown to be in error because of the neglect of terms of the same order in perturbation theory which remove the reported divergency and leave only very small corrections to the Boltzmann equation. In addition, it is suggested that the experimental basis for these large deviations may have a different explanation.