Elastic properties of 5d transition-metal carbides: An ab initio study

We have systematically studied the mechanical stability of group V transition metal carbides TMC2 (TM=Hf, Ta, W, Re, Os, Ir, Pt, and Au) in the pyrite and fluorite phase, by calculating their elastic constants within the density functional theory scheme. It was found that all but ReC2 and OsC2 are stable in pyrite phase. On the other hand, all metal carbides studied were unstable in the fluorite phase