Phonons and superconductivity in the cubic perovskite Cr3RhN

We have performed an ab initio study of structural, electronic, vibrational, and superconducting properties of Cr3RhN. The calculations have been carried out by employing the density functional theory, a linear-response formalism, and the plane-wave pseudopotential method. A striking feature of the phonon spectra in this cubic perovskite is the existence of a number of soft modes at the zone centre as well as at Brillouin zone boundaries. Calculations of the Eliashberg spectral function alpha F-2(omega) and the electron-phonon prefactor alpha(2)(omega) reveal that the low frequency soft phonon branches couple more strongly with electrons. Using the calculated electron-phonon coupling parameter lambda = 1.03 and the logarithmically averaged frequency omega(ln) = 255 K, we suggest that this material is a superconductor with the transition temperature close to 17 K. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4764916]