Comparison of Finite Element Approach and LCAO Analysis with SIWB Method for a Molecule Including an Anion in a Discrete Variational Density Functional Theory

抄録

For proper anion description, the author developed the SIWB (surrounding or solid Coulomb-potential-induced well for basis set) method for a linear combination of atomic orbitals (LCAO) calculated numerically in a discrete variational (DV) density functional theory (DFT). In the DV method, a relatively deep (such as −1 Eh) well potential is added to the potential for electrons to generate stable atomic orbital basis functions, where the depth and radius of the well are not definitely determined. Meanwhile, the SIWB method uniquely determines the well radius and the well depth, which is relatively shallow (such as −0.34 Eh). In this article, calculations of the one-electron wave function for a molecule containing an anion were performed using the finite element method (FEM). The FEM results were compared not only to results from the usual LCAO method with a relatively deep well, but also to those from the improved LCAO method with the SIWB scheme (denoted as LCAO−SIWB). It was shown that the FEM results for the anion are consistent with the LCAO−SIWB results.