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DFT study of a single F center in cubic SrTiO 3 perovskite
Author(s) -
Evarestov R. A.,
Kotomin E. A.,
Zhukovskii Yu. F.
Publication year - 2005
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.20855
Subject(s) - band gap , density functional theory , condensed matter physics , supercell , perovskite (structure) , lattice (music) , atom (system on chip) , lattice constant , materials science , chemistry , molecular physics , crystallography , physics , computational chemistry , quantum mechanics , diffraction , computer science , thunderstorm , meteorology , acoustics , embedded system
Abstract Various properties of a cubic phase of SrTiO 3 perovskite containing single F centers (neutral oxygen vacancies), including energies of their formation and migration, were simulated using different formalisms of density functional theory (DFT) as implemented into CRYSTAL‐2003 and VASP computer codes. The lattice relaxation around the F center was found to be sensitive to both shape and size of supercells used. The larger the supercell, the closer the defect energy level in the bandgap lies to the conduction band bottom. It approaches the optical ionization energy of 0.49 eV for 270‐ and 320‐atom supercells, where the distance between neighboring defects increases up to four lattice constants. The defect bandwidth decreases for these supercells down to 0.02 eV, i.e., the defect–defect interaction becomes negligible. Thus, the two different first‐principles periodic approaches combined provide results that are converged with respect to the supercell size and correspond to a single defect limit. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006