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arXiv · 0803.0619

Structural, vibrational and quasiparticle properties of the Peierls semiconductor $\rm BaBiO_3$: a hybrid functional and self-consistent GW+vertex-corrections study

C. Franchini·A. Sanna·M. Marsman·G. Kresse
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Abstract

$\rm BaBiO_3$ is characterized by a charge disproportionation with half of the Bi atoms possessing a valence 3+ and half a valence 5+. Because of selfinteraction errors, local and semi-local density functionals fail to describe the charge disproportionation quantitatively, yielding a too small structural distortion and no band gap. Using hybrid functionals we obtain a satisfactory description of the structural, electronic, optical, and vibrational properties of $\rm BaBiO_3$. The results obtained using GW (Green's function G and screened Coulomb potential W) based schemes on top of hybrid functionals, including fully selfconsistent GW calculations with vertex corrections in the dielectric screening, qualitatively confirm the HSE picture but a systematic overestimation of the bandgap by about 0.4 eV is observed.

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C. Franchini, A. Sanna, M. Marsman, G. Kresse. 2009-11-18. Structural, vibrational and quasiparticle properties of the Peierls semiconductor $\rm BaBiO_3$: a hybrid functional and self-consistent GW+vertex-corrections study. https://arxiv.org/abs/0803.0619

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