First-principle investigation of Jahn-Teller distortion and topological analysis of chemical bonds in LiNiO2

Abstract First-principle GGA+U calculations were performed on the undistorted rhombohedral R 3 m model, the collinear Jahn–Teller distorted monoclinic C 2/ m model, and six non-collinear Jahn–Teller distortion ordering models of LiNiO 2 . The zigzag and C 2/ m models are found to be the most stable and the next most stable structural models, respectively. An energy gap appears for the C 2/ m and zigzag structures, whereas no energy gap appears for the R 3 m structure. Topological analyses were performed on the R 3 m , C 2/ m and zigzag models using the atoms-in-molecules theory and the electron localization function. The results show that the Ni–O interaction is the transit closed-shell interaction, in which the net electron transfer occurs from the Ni ion to the ligand O ions. The Ni–O bond possesses the σ dative bond character and is polarized toward the O ions. In the distorted structures, the bonding electrons around the oxygen atom are strongly polarized toward the long Ni–O bond.