Role of non-local exchange in the electronic structure of correlated oxides

Physical Review B 85, 115129 (2012)

Role of non-local exchange in the electronic structure of correlated oxides

F. Iori, M. Gatti, A. Rubio

We present a systematic study of the electronic structure of several prototypical correlated transition-metal oxides: VO2, V2O3, Ti2O3, LaTiO3, and YTiO3. In all these materials, in the low-temperature insulating phases the local and semilocal density approximations (LDA and GGA) of density-functional theory yield a metallic Kohn-Sham band structure. Here we show that, without invoking strong-correlation e ects, the role of non-local exchange is essential to cure the LDA/GGA delocalization error and provide a band-structure description of the electronic properties in qualitative agreement with the experimental photoemission results. To this end, we make use of hybrid functionals that mix a portion of non-local Fock exchange with the local LDA exchange-correlation potential. Finally, we discuss the advantages and the shortcomings of using hybrid functionals for correlated transition-metal oxides.

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http://dx.doi.org/10.1103/PhysRevB.85.115129
arxiv
http://arxiv.org/abs/1201.3308

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