Pressure-dependent mechanical and thermodynamic properties of newly discovered cubic Na2He

Abstract

Recently for the first time a stable compound of He and Na (Na2He) is predicted at high pressure. We explore the pressure dependent elastic, mechanical and thermodynamic properties of this newly discovered Na2He by using ab initio technique. The calculation presents good accordance between the theoretical and experimental lattice parameters. Though the most stable structure of Na2He is found at 300 GPa, present study ensures the mechanical stability of this compound up to 500 GPa. However, the Debye temperature, melting temperature and minimum thermal conductivity of Na2He are also calculated and discussed at different pressure.