The structural, mechanical, electronic, lattice dynamics and thermodynamic properties of TaTSi (T = Rh, Os, Ir) compounds by first-principles calculations

We have performed a theoretical calculation, based on density functional theory, to investigate the structural, mechanical, electronic, lattice dynamics, and thermodynamic properties of TaTSi (T = Rh, Os, Ir) within the full potential linearized augmented plane wave method. The calculated values of the lattice constant and unit cell volume are in excellent agreement with the available experimental data. The mechanical stability is substantiated by our calculated elastic constants, while the mechanical properties are subsequently derived. The results indicate that the compounds are ductile materials, except for TaRhSi which exhibits quasi-ductile behavior; however, all of them exhibit elastic anisotropy. In addition, the electronic density of states of the TaTSi (T = Rh, Os, Ir) compounds reveal that all these materials have a metallic character. Moreover, the dynamical stability is confirmed by our calculated phonon spectra. Finally, we present temperature-dependent thermodynamic properties including free energy, internal energy, entropy, and heat capacity.