Electron-phonon coupling in the metallic elements Al, Au, Na, and Nb: A first-principles study

We present an ab initio study of the electron-phonon coupling in some monatomic fcc and bcc metals. We employed a linear-response approach based on density-functional theory in the plane-wave pseudopotential representation to evaluate the phonon dispersion curves of Al, Au, Na, and Nb. We then studied the nonadiabatic behavior of the considered metals by determining the phonon linewidths due to the electron-phonon coupling and the Eliashberg and transport spectral function. We especially focused on the relevance of the different types of metallic bonds for these properties. We found remarkable differences in the phonon linewidths and spectral functions of elements with the same crystal structure, which is a subtle and important consequence of the different electronic structures. Finally, the spectral functions have been used to calculate the temperature dependence of the electrical and thermal resistivity. We compare our results to experimental data where available.