Quasiharmonic calculations of thermodynamic properties for La3−xTe4 system

[Display omitted] •First-principles phonon calculations are carried out for Lanthanum telluride.•The effects La site vacancy on the thermodynamic properties are studied.•It is found the band gap can be described very well by PBEsol.•It shows that the PBEsol functional is superior to the PBE functional. An extensive first-principles quasiharmonic phonon calculation was carried out for the thermoelectric material La3−xTe4 at the compositions of x = 0.0, 0.25 and 0.33, focusing at the La site vacancy effects on the thermodynamic properties. The calculated quantities include the 0 K static total energy curves and electronic band structures as well as density-of-states, the phonon density-of-states, together with the linear thermal expansion coefficients, the entropies, the enthalpies, the heat capacities, the bulk moduli, and the Debye temperature as functions of temperature up to 1200 K. Both the standard Perdew-Burke-Ernzerhof (PBE) and the Perdew-Burke-Ernzerhof revised for solids (PBEsol) exchange-correlational functionals were examined and it was found that the PBEsol functional was generally better than the PBE functional in describing both the crystal and electronic properties for the La3−xTe4.