Elastic properties of LaNiO$_{3}$ from first-principles calculations

By applying density functional theory (DFT) approximations, we present a first-principles investigation of elastic properties for the experimentally verified phases of a metallic perovskite LaNiO$_{3}$. In order to improve the accuracy of calculations, at first we select the most appropriate DFT approaches according to their performance in reproducing the low-temperature crystalline structure and the electronic density of states observed for the bulk LaNiO$_{3}$. Then, we continue with the single-crystal elastic constants and mechanical stability for the most common rhombohedral as well as high-temperature cubic and strain-induced monoclinic phases. Together with the calculated single-crystal elastic constants, the deduced polycrystalline properties, including bulk, shear, and Young's moduli, Poisson's ratio, Vickers hardness, sound velocities, Debye temperature, and anisotropy indexes, remedy the existing gap of knowledge about the elastic and mechanical behaviour of LaNiO$_{3}$, at least from a theoretical standpoint.