We investigate the hydrostatic pressure dependences of elastic, electronic, and optical properties of newly hypothesized perovskite compound ACuO3 (A=Ca, Sr) using the first-principles method. The structural and mechanical stabilities have been established theoretically under pressure up to 100 GPa. The ductile nature of these transition metal oxides have been confirmed by the calculation of elastic constants. The relatively low value of Young modulus possesses high thermal shock resistance and proclaims the materials to be a promising thermal barrier coating material. Partial density of states shows the dominant behavior of Cu-3d and O-2p orbitals at the Fermi-level and it implies the subsequent good electrical conductivity. The significant response of the optical properties such as reflectivity, dielectric constant, optical absorption, and loss function with the change in pressure have been noted. The origin of these optical responses is discussed with implications, which can be supportive for future investigations of ACuO3 (A=Ca, Sr).

The cubic phase of CsNbO3 (CNO) perovskite has been hypothesized to investigate the elastic, electronic, photocatalytic, and optical properties for various technological applications using first-principles method. The pressure dependent structural stability has been confirmed from computed elastic constants. Relatively high value of elastic moduli, large hardness and toughness suggested that CNO would be applicable to design industrial machineries. The ductile to brittle transition is noticed at 20 GPa. The indirect bandgap of CNO proclaims its suitability for photovoltaic and IR photodetector applications. The total and partial density of states are calculated to show in evidence the contribution of individual atomic orbitals in the formation of bands. The pressure changes orbitals hybridization which can be substantiated by the change in the bandgap. Strong covalency of the Nb–O bond and antibonding character of Cs–O have been anticipated by the Mulliken population analysis and by the contour maps of electron charge density. The low carrier effective mass and high mobility carriers predict the good electrical conductivity of the material. The calculated values of conduction and valance band edge potential illustrate the excellent water-splitting and environmental pollutants degradation properties of CNO.