LaCoO3 - from first principles

Abstract

We have performed calculations of the electronic structure of LaCoO3 from first principles, assuming the atomistic construction of matter and the electrostatic origin of the crystal-field splitting. In our atomic-like approach QUASST the d electrons of the Co3+ ion in LaCoO3 form the highly-correlated atomic-like system 3d6 with the singlet ground state 1A1 (an octahedral subterm from the 1I term) and the excited octahedral subterm 5T2g of the 5D term. In the spin-orbital space, being physically adequate, this high-spin state is Jahn-Teller active. We take the ESR experiment of Noguchi et al., Phys. Rev. B 66, 094404 (2002), as confirmation of the existence of the discrete electronic structure for 3$d$ electron states in LaCoO3 in the meV scale postulated in QUASST.