Discussion on the Variable Wolfsberg-Helmholtz Parameter,a New Simplified Lowdin Transformation and the Characteristic Structure of the Transformed EHT Hamiltonian Matrices

摘要

Three related problems are discussed: (1) the variable nature of the Wolfsberg-Helmholtz parameter and its relationship with the overlap eigenvalue range; (2) the possibility of deriving an efficient framework,describing a simplified Lowdin transformation to solve generalized secular equations; and (3) the structure of the transformed classical EHT Hamiltonian.This work shows how the simplified Lowdin transformation permits expression of the resulting transformed Hamiltonian elements by means of inward matrix products and total matrix sums.