EFFECTIVE QUASI-PARTICLE POTENTIAL IN MOLECULES AND SOLIDS .2. APPLICATIONS OF THE WIGNER-SEITZ POTENTIAL

The Wigner-Seitz potential is used as an effective quasiparticle potential to find the binding energies and excitation energies of diatomic molecules and diamond. The single-particle Schrodinger equation is solved by the matching Green function method; with the Wigner-Seitz potential the binding energy can be found from the sum of one-electron eigenvalues. Good results are obtained for the binding energies of alkali molecules, but the method is poor in the case of H2 where the effective potential is much closer to Hartree-Fock. The Wigner-Seitz potential gives satisfactory energy levels in multiply bonded molecules such as C2, N2 and CO, and in the covalent diamond crystal it gives a good band structure and binding energy. © 1979 Taylor & Francis Group, LLC.