Prediction of stable high-pressure structures of tantalum nitride TaN2

Abstract

Structure searches based on a combination of first-principles calculations and a particle swarm optimization technique unravel two new stable high-pressure structures (C2/m and Cmce) for TaN2. The structural features, mechanical properties, formation enthalpies, electronic structure, and phase diagram of TaN2 are fully investigated. Being mechanically and dynamically stable, the two phases could be made metastable experimentally at ambient conditions.