First-principle calculations to investigate mechanical and acoustical properties of predicted stable halide Perovskite ABX.

This work examines the predicted stable halide perovskites' elastic, acoustical, and thermal characteristics. The work uses the Full Potential-Linearized Augmented Plane Wave (FP-LAPW) technique through PBE-GGA to compute compounds in the WIEN2K algorithm. The ELATE program for the evaluation of elastic tensors to plot 2D and 3D graphs was also used. The bulk modulus, Young's modulus, shear modulus, anisotropy factors, Cauchy pressure, Pugh's ratio, Poisson's ratio, Kleinman's parameter, Lame's coefficient, Vicker's hardness, sound velocities, Gruneisen parameter and even melting and Debye temperature were computed. The mechanical and elastic properties are reported for the first time for most of the compounds, demonstrating that the investigated HPs-aside from TlBeF, BaAgBr, and CsTcl-are mechanically stable and exhibit weaker resistance against shear distortion than they do to unidirectional compression. The results of Poisson's, Pugh's, and Frantsevich's ratios data prove that all materials are ductile except SrLiF. The estimated Poisson's ratio data indicates the metallic bonding nature of HPs, whereas only SrLiF exhibits covalent behavior with ν = 0.23. Debye temperature for SrLiF, ZnLiF, ZnScF, CsRhCl, CsRuCl, and CsBeCl is greater than 200 K which signifies their hardness, thermal conductivity, and high sound velocities. The large melting temperature values, make them suitable for high-temperature industrial applications. The anharmonicity effect is highest for CaCuBr (3.265) and lowest for SrLiF (1.402). The current approach calculates elastic and mechanical properties, providing a practical understanding of various physical processes and enabling technology developers to utilize compounds in diverse applications.