First-principles generalized gradient approximation (GGA) +U studies of electronic structure and optical properties in cubic ZrO2

• By introducing Ud and Up, we can reproduce the experimental value of the band gap.
• The Ud and Up values are determined by the band-gap fitting.
• The calculated results by GGA+Ud+Up well agreed with available experimental data.
• Our results by GGA+Ud+Up are more accurate than those by a scissor operation.
• GGA+Ud+Up approach is a powerful and reliable first-principles method.

The electronic structures and optical properties of cubic ZrO2 are investigated by means of generalized gradient approximation (GGA) +U approach. By including the Coulomb interaction of 4d orbitals on Zr atom (Ud), as well as of 2p orbitals on O atom (Up), the experimental value of the band gap can be reproduced when Ud=8.25 eV, and Up=4.6 eV. With these U values, the electronic structure and optical properties are calculated, in comparison to experiments and other theoretical results, e.g., by scissor operations. Our results are found to be in good agreement with available experimental data, and more accurate than those obtained by a scissor operation.