Hartree-Fock Calculations of the Band-Gap Discontinuity Near the Metal Insulator Transition

The Hartree-Fock self-energy operator is calculated for a model two-dimensional indirect-gap semiconductor. The quasiparticle energies and the discontinuity in the exchange-correlation potential introduced by Sham and Schluter are investigated near the band overlap metal-insulator transition. Corrections to the effective mass arising from the nonlocality of the self-energy operator are also discussed.