Nonlocal density scheme for electronic-structure calculations

An exchange-correlation energy functional beyond the local-density approxim ation (LDA), based on the exchange-correlation kernel of the homogeneous el ectron gas and originally introduced by Kohn and Sham, is considered for el ectronic-structure calculations of semiconductors and atoms. Calculations a re carried out for diamond, silicon, silicon carbide, and gallium arsenide. The lattice constants and gaps show a small improvement with respect to th e LDA results. However, the corresponding corrections to the total energy o f the isolated atoms are not large enough to yield a substantial improvemen t for the cohesive energy of solids, which remains hence overestimated as i n the LDA. [S0163-1829(99)01940-2].