Intense research and tremendous investments have taken place in the field of photovoltaics for years to enhancing the efficiency of photovoltaic (PV) solar cells. Therefore, meticulous selection of semiconductor materials is crucial, given their remarkable ability to absorb a broad spectrum of solar radiation. In this study, a systematic investigation was conducted into the structural, elastic, electronic, and optical properties of two semiconductor materials: the tetragonal chalcopyrite, \({\text{MgSnP}}_{2}\) , and the cubic perovskite, \({\text{SrTiO}}_{3}\) . These materials were chosen for their distinct characteristics, including optimal band gaps conducive to PV conversion and strong absorption, particularly within the visible solar spectrum. Structural optimization and property calculations were performed using the CAmbridge Serial Total Energy Package code within Density Functional Theory, utilizing the Generalized Gradient Approximation with the Perdew–Burke–Erzenhof exchange–correlation function. The calculated lattice parameters align excellently with previously reported theoretical values. Analysis of the electronic band structure provides compelling evidence of semiconductor behavior in the compounds. Electronic properties reveal band gaps of Eg = 1.255 eV for \({\text{MgSnP}}_{2}\) and Eg = 1.83 eV for \( {\text{SrTiO}}_{3} \) , respectively, from G-G and R-G high symmetry points, enabling them to absorb a wide range of the solar spectrum. The B/G ratio for \({\text{MgSnP}}_{2} \) is calculated to be 2.6, surpassing the critical value of 1.75 according to Pugh's criterion, indicating its ductile or malleable nature with significant deformation capacity before failure. Conversely, the B/G ratio for \({\text{SrTiO}}_{3}\) is 1.49, below the threshold of 1.75, classifying it as a brittle material with limited plastic deformation and a tendency for sudden fracture.
