Electronic band structure of Cu2O by spin density functional theory

The band structure of Cu2O is calculated using density functional theory in the generalized gradient approximation. By taking spin-orbit coupling into account the split between the Gamma(+)(7) and the Gamma(+)(8) valence band states is obtained as 128 meV. The highest valence band shows a noticeable nonparabolicity close to the Gamma point. This is important for the quantitative description of excitons in this material, which is considered to be the best candidate for the confirmation that Bose-Einstein condensation also occurs in excitonic systems.