High-throughput computational materials screening of transition metal peroxides

• Published in: Physical chemistry chemical physics : PCCP Vol. 26; no. 3; pp. 293 - 21
• Main Authors: Peng, Yin-Hui, He, Chang-Chun, Zhao, Yu-Jun, Yang, Xiao-Bao
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 17.01.2024
• Subjects: Coordination numbers; First principles; Peroxides; Screening; Semiconductor materials; Titanium dioxide; Transition metals; Valence band
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d3cp03968d

Semiconductor materials of abnormal stoichiometric ratio often exhibit unique properties, yet it is still a challenge to determine the structures of such materials in an efficient way. Herein, we propose a method for structurally biased screening according to the coordination numbers and the numbers of Wyckoff positions, balancing the atom local environment and the global symmetry of structures. Based on first-principles calculations, we have predicted two metastable peroxides P 2 1 / c -ScO 2 and Pmmn -TiO 3 with more than six coordination points. For these two structures, the most stable intrinsic defect is the oxygen vacancy (V O ) at the peroxide anion (O 2− 2 ), which induces the absence of antibonding orbital formed by O 2− 2 near the valence band maximum. With the introduction of V O , the decrease of coordination numbers leads to charge recombination, and results in the appearance of an ordered phase TiO 2.5 with stronger Ti-O orbital hybridization. The proposed method presents a promising and feasible approach for the screening of novel compounds. We propose a method for structurally biased screening according to the coordination numbers and the numbers of Wyckoff positions, balancing the atom local environment and the global symmetry of structures.