Ground state, phonon spectrum, and superconducting properties of the nonoxide perovskiteCdCNi3

Abstract

We have made theoretical investigations of the structural, elastic, electronic, lattice-dynamical, and superconducting properties of the antiperovskite compound ${\text{CdCNi}}_{3}$. The structural, elastic, and electronic properties of this material have been calculated by using the generalized gradient approximation of the density-functional theory and ab initio pseudopotentials. Using our structural and electronic results, the phonon spectrum, phonon linewidths, and electron-phonon coupling parameter have been calculated by employing a linear-response approach based on density-functional theory. We have observed a softening behavior of the lowest acoustic phonon branch along the $X\text{\ensuremath{-}}R$ symmetry direction. The electron-phonon coupling parameter is found to be 0.80.