Lattice parameters and electronic bandgap of orthorhombic potassium sodium niobate K$$_{0.5}$$Na$$_{0.5}$$NbO$$_{3}$$ from density-functional theory

Abstract We perform a theoretical analysis of the structural and electronic properties sodium potassium niobate K $$_{1-x}$$ 1 - x Na $$_{x}$$ NbO $$_{3}$$ 3 in orthorhombic room-temperature phase, based on density-functional theory combination with supercell approach. Our results for $$x=0$$ = 0 $$x=0.5$$ 0.5 are very good agreement experimental measurements establish that lattice parameters decrease linearly increasing contents, disproving earlier studies virtual-crystal approximation claimed highly nonlinear behavior significant distortion volume reduction $$_{0.5}$$ compared to both end members solid solution. Furthermore, we find bandgap varies little between , reflecting small changes parameters. Graphic abstract