A new version of the variational cellular method for polyatomic systems

Abstract
The authors present a new version of the variational cellular method of Ferreira and Leite (1979) for the calculation of the electronic structure of polyatomic systems. This version seems to be simple to use, eliminates the muffin-tin potentials and charge densities, and is as fast as the multiple-scattering method. The authors develop programmable procedures for the definition of the cells and choice of points for the surface integrations of polyatomic structures. When applied to methane, the method gave very good results for the energy, interatomic distance, a1 mode frequency and ionisation energies at a very low computational cost.