Calculations of superconducting properties in yttrium and calcium under high pressure

Abstract

We have used first-principles electronic structure calculations to generate the bulk modulus as a function of volume as well as the densities of states and scattering phase shifts at the Fermi level. These quantities were used in conjunction with the rigid-muffin-tin theory of Gaspari and Gyorffy and the McMillan theory to determine the electron-phonon coupling and the superconducting transition temperature for yttrium and calcium under high pressures. Our results provide a good interpretation of the measured increase of ${T}_{c}$ in these metals.