A modification of the iterative matrix diagonalization method of Davidson is presented that is applicable to the symmetric eigenvalue problem. This method is based on subspace projections of a sequence of one or more approximate matrices. The purpose of these approximate matrices is to improve the efficiency of the solution of the desired eigenpairs by reducing the number of matrix-vector produ...

The electron paramagnetic resonance parameters (g factors g‖,g⊥ and hyperfine structure constants A‖,A⊥) of PbTiO3: Cu 2+ are calculated from the complete diagonalization method and the perturbation theory method. The calculated results obtained by the complete diagonalization method are close to that obtained by the perturbation theory method, and in good agreement with the experimental values...