The Xα method with AB initio exchange parameters, diamagnetic susceptibility and nuclear magnetic shielding constants for several atoms

Abstract

Since the appearance of the Xα method there have been several attempts to make it an ab initio theory introducing an ab initio exchange parameter α into the Xα method. In his previous papers one of the authors suggested a self-consistent way of calculating exchange parameter α in the Xα method. The diamagnetic susceptibility and the nuclear magnetic shielding constants are presented for atoms with the atomic numbers Z=3–36. The XαSCF values are close to the Hartree-Fock results. It is shown that the Xα spin orbitals approximate the Hartree-Fock ones near the nucleus better than far from the nucleus. In the values calculated by, the Xα method for the diamagnetic susceptibility the shell structure of atoms is reflected. The nuclear magnetic shielding constants do not have a similar feature.