Abstract
A simple semi-empirical method is developed with a valence bond theory for calculating electronic structures, which is applicable for from molecules to condensed matters. Matrix elements in terms of the overlap integrals and the Hamiltonians are determined semi-empirically with a σ bond basis set. Molecular states are calculated using block matrix transformations based on the Green’s function theory. The bulk state calculations are performed by means of the clustered recursion method. The electronic structures in molecules CH4, C2H6, diamond like clusters and diamond are presented as examples, which are compared with ionization spectrum data. Complex number atomic orbitals obtained directly from the Schrödinger equations are handled for approximating effective interactions in valence bond systems.
