The Perovskites MSnO3 (M = Mg, Ca): Ab Initio Investigation of Structural, Electronic, Thermodynamic, and Thermoelectric Characteristics

This paper introduces an ab initio theoretical investigation employing the Full-Potential Linear Augmented Plane Wave (FP-LAPW) method grounded in Density Functional Theory (DFT). The aim is to ascertain the structural and electronic characteristics of the perovskite compounds MgSnO₃ and CaSnO₃. The calculation of structural and electronic properties involved employing the Generalized Gradient Approximation (GGA) for exchange–correlation energy. Through the minimization of energy with respect to volume using the Murnaghan equation of state, the study derived the equilibrium lattice parameter and cohesive properties of the compound. The analysis of the electronic structure was centered on examining the electronic density of states (DOS). Density Functional Theory (DFT) was employed to calculate the pressure and temperature-dependent variations in specific heat, entropy, and Debye temperature. The equation of state, implemented through the GIBBS program based on the quasi-harmonic Debye model, facilitated these computations. Notably, a specific heat behavior of Cv≈Cp was identified at temperatures below T = 300 K, surpassing Dulong-Petit limit values reported for simple perovskites. Furthermore, thermoelectric properties were assessed using the Boltzmann transport theory in the BoltzTraP code.