A detailed structural analysis of the self-energy for an electron gas is made with emphasis on the importance of various cancellations due to the Pauli principle. Based on the analysis, we propose an exchange and correlation potential for use in energy-band calculations. The potential contains the information about the effective mass as well as the chemical-potential shift in the form of a nonlocal exchange operator.

• Received 18 September 1990

DOI:https://doi.org/10.1103/PhysRevB.43.7200