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 fee and bcc metals. We employed a linear-response approach b ased on density-functional theory in the plane-wave pseudopotential re presentation to evaluate the phonon dispersion curves of Al, Au, Na, a nd Nb. We then studied the nonadiabatic behavior of the considered met als by determining the phonon linewidths due to the electron-phonon co upling and the Eliashberg and transport spectral function. We especial ly focused on the relevance of the different types of metallic bonds f or these properties. We found remarkable differences in the phonon lin ewidths and spectral functions of elements with the same crystal struc ture, which is a subtle and important consequence of the different ele ctronic structures. Finally, the spectral functions have been used to calculate the temperature dependence of the electrical and thermal res istivity. We compare our results to experimental data where available.