Finding optimal radial-function parameters for S atoms in the Hansen–Coppens multipole model through refinement of theoretical densities

The multipolar model of the valence-electron-density distribution for sulfur has been optimized based on theoretical structure factors for six organic molecules. It is shown that: (a) the ratio of the n(l) values for different l is more important than their absolute values, and (b) the (2,4,6,8) set of n(l) with κ′ refined as a single value is an optimal choice of radial function parameters for S atoms.

On the calculation of the electrostatic potential, electric field and electric field gradient from the aspherical pseudoatom model

Accurate, simple and efficient formulae for calculation of the electrostatic potential, electric field and electric field gradient from the aspherical pseudoatom model of electron density are presented. The expressions are applied to the determination of the nuclear quadrupole moment of the Fe atom in Fe(CO)₅.