title: Structures and Energetics of SrFeO2.875 Calculated within the GGA + U Framework.
abstract: The energetics and electronic properties of SrFeO2.875 have been systematically calculated with the fully relaxed atomic positions at both GGA and GGA + U levels, and different spin-polarized configurations have been considered. Many atoms besides the nearest neighbors of the oxygen vacancy have been found to be influenced by the vacancy in terms of positions and electronic structures. The obtained magnetic moments suggest the high-spin character of the Fe 3d electrons, in combination with the larger exchange splitting compared with the crystal field splitting. The local states at the Fermi level are found to be situated within the π* band in the nonmagnetic case and the σ* bands in the ferromagnetic and antiferromagnetic cases. The energy values concerning the oxygen-vacancy formation from SrFeO3 to SrFeO2.875 have been deduced with the correction of the O2 overbinding error and the consideration of the oxygen partial pressure and the temperature.
authors.affiliation: State Key Laboratory of Multi-Phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Wen Lai
authors.initials: WL
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Multi-Phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Qingshan
authors.initials: Q
authors.lastname: Zhu