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Abstract:
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, respectively) of density-functional theory
yield a metallic Kohn-Sham band structure. Here we show that, without invoking strong-correlation effects, the
role of nonlocal 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 nonlocal 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.
