First-principles investigations on elastic properties of αα- and ββ- Ta4AlC3

The plane-wave pseudopotential method in the frame of density functional theory (DFT) is adopted to investigate equation of state (EOS), equilibrium structure and elastic constants of αα- and ββ- Ta4AlC3. The calculated structure parameters are in good agreement with the available experimental and theoretical data. Five independent elastic constants of both structures are calculated. Mechanical anisotropy, Elastic wave velocity and Debye temperature for both structures are finally obtained.