Tight‐Binding Parameterizations of Ti and Ba Oxides and Their Application for the Prediction of 2D Phases

Abstract

Herein, a set of Slater–Koster parameters for the O–Ti–Ba system to be used within the self‐consistent‐charge, density‐functional tight‐binding method is developed. This parameterization follows the recently suggested procedure by Huran et al. in 2018, and is based on the fitting to density‐functional theory (DFT) results. This approach yields improved energies and forces compared with existing parameterizations, and is, therefore, useful for the applications in molecular dynamics or global structural prediction. The O–Ba subset of the parameters is then used to investigate the low‐dimensional phase diagram of Ba–O using global structural prediction techniques. The resulting convex hull of stability is validated using DFT, and the most interesting phases are subsequently analyzed and characterized. Among the stable systems, superoxides, peroxides, BaO, and oxygen‐deficient phases are found with different geometrical arrangements and electronic properties.