In optoelectronic device applications, perovskite materials have surpassed other compounds due to their remarkable power conversion efficiencies. Recently, lead-free metal halide perovskites are drawing increasing attention as sustainable alternatives as lead-based perovskites, offering to their low cost, mechanical flexibility, tunable properties, high efficiency, and environmental sustainability. In this study, density Functional Theory (DFT) was employed to investigate the electronic, optical, elastic, and thermodynamic properties of M 2 GaAgF 6 (M = Na, K) metal halide under hydrostatic strain. The structural and dynamic stability confirm with formation energy, tolerance factor and ab initio molecular dynamics (AIMD) simulations. Structural optimization and band structure within the Generalized Gradient Approximation (GGA) revealed that compressive (tensile) strain decrease (increases) lattice constants and band gaps, indicating effective band gap tuning. The projected density of states analysis reveals the modulation of orbital contributions near to the fermi level via strain effect. Optical properties study shown that there was an observable redshift in the absorption edge as strain induced, which shows an increased absorption of light at lower energies. The calculated optical characteristics indicate that the optical response is enhanced by the hydrostatic strain, which increases the possible applications of these materials in devices. Mechanical analysis showed that both compounds are ductile and anisotropic, and the mechanical stability of the compounds largely depends on the strain applied. The negative Gibbs free energy and Debye temperature reveal the thermodynamic stability and practical applicability of the investigated compounds at room temperature.
Ghani et al. (2026) studied this question.