Pressure-Temperature Dependence of Thermodynamic Properties of $$\hbox {ScAlO}_{3}$$ Perovskite from First Principles.

First-principles calculations have been performed to obtain the thermodynamic properties of $$\hbox {ScAlO}_{3}$$ perovskite in a wide range of pressure (0 GPa to 30 GPa) and temperature (0 K to 1400 K). Calculations have been performed by using the pseudo-potential method within the generalized gradient approximation. Both pressure- and temperature-dependent thermodynamic properties including the bulk modulus, thermal expansion, thermal expansion coefficient, and the heat capacity at constant volume and constant pressure were calculated using three different approaches based on the quasi-harmonic Debye model: the Slater, Dugdale-MacDonald (DM), and Vaschenko-Zubarev (VZ) approaches. Also, empirical energy corrections are applied to the results of models to correct the systematic errors introduced by the functional. It is found that the VZ model provides more accurate estimates in comparison with the DM and Slater models, especially after an empirical energy correction. The results obtained from the VZ analysis on the corrected static energy show that this method can be used to determine the thermodynamic properties of $$\hbox {ScAlO}_{3}$$ compounds with reasonable accuracy. [ABSTRACT FROM AUTHOR]