Electrostatic Potentials at Nuclei for Atoms From Z = 1 to Z = 54 Using the aHGBSP1-5 Basis Set

Abstract

The electrostatic potential at the nucleus of an atom, whether it be in the free state or in a neutral molecule or in an ionic molecular species, is qualitatively a characteristic property of the atom. It changes remarkably little from one molecular environment to another. As has been shown earlier by Politzer, the energies of atoms and molecules can be expressed both rigorously and approximately in terms of the electrostatic potentials at their nuclei. These findings support the validity of the atoms-in-molecules concept; however, without boundaries. This has been further substantiated in recent papers where the authors have shown that the electrostatic potential created by the electrons of all of the other atoms at a particular nucleus in a molecular species, not including those associated with that particular atom itself, is almost identical in magnitude to the potential due to the other nuclei. However, as has been shown by Gadre and Suresh, small differences in the electrostatic potentials at nuclei for interacting atoms in noncovalent interactions have been correlated with their interaction energies. Thus, finding ways to compute these beyond the main group elements is imperative for further exploration. Because of the importance of electrostatic potential at nuclei, in this paper are reported first, for comparison purposes, the electrostatic potentials at nuclei for atoms from Z = 1 to Z = 36 (hydrogen to krypton) using four density functional methods and the 6–311 + G(3df,2p) basis set and then for Z = 1 to Z = 54 (hydrogen to xenon) using six methods and the aHGBSP1-5 basis set. The values are presented and graphically displayed and discussed.