1966/05/13 by L. J. Sham, W. Kohn · 5 citations
Physics and Astronomy · Engineering · Chemistry · #Advanced Chemical Physics Studies #Molecular Junctions and Nanostructures #Advanced Physical and Chemical Molecular Interactions
paper · doi:10.1103/physrev.145.561
In previous publications (especially by Hohenberg, Kohn, and Sham), a theory of the ground state of an inhomogeneous interacting electron gas was developed, in which the electronic density n(r) played a dominant role. The present paper extends this approach to the one-particle Green's function and physical properties related to it, such as single-particle-like excitations and, in the case of metals, the Fermi surface. The Dyson mass operator \ensuremathΣ is studied as a function of its spatial arguments and as a functional of n(r), and, in both senses, it is found to have important short-range properties. An approximation for \ensuremathΣ, which is exact for systems of slowly varying density, is proposed. This leads to simple, explicit, Schr"odinger-like equations for the single-particle-like excitations, whose solution determines their energies and lifetimes. In particular, we show how to apply this procedure to metals.