Screened exchange density functional applied to solids

The screened exchange (SX) hybrid functional, which mixes a Thomas-Fermi screened Hartree-Fock exchange into the local-density approximation (LDA), is applied to solids. SX can be used as a variational functional in total-energy minimizations and it represents an efficient way to improve the accuracy of band calculations. Here we summarize the computational implementation within the plane-wave, pseudopotential formalism and compare results to related methods. This representation of the exchange-correlation energy improves the incorrect treatment of the self-interaction in the LDA. SX also improves the calculated band gap of a wide range of semiconductors and insulators compared to the LDA with a mean relative error of 7.4% compared to near 30% for LDA or generalized gradient approximation.