Ab initio superconducting temperature of BaSi2 at ambient pressure

Abstract

Barium silicide in the metastable trigonal phase is studied using ab initio methods. The band structure and the phonon spectrum are computed and analyzed. The electron-phonon coupling is found to have a substantial contribution coming from the A1g optical mode at Γ. The superconducting transition temperature is calculated using the Allen-Dynes formula, but is found to be an order of magnitude smaller than the experimental value; some tentative explanations for the disagreement are presented. © 2010 IOP Publishing Ltd.