On calculations of dipole moments of HCl+ and DCl+ molecular ions

TL;DR

This paper investigates the dipole moments of HCl+ and DCl+ ions using analytical and ab initio methods, explaining differences based on coordinate system choices and isotopic substitution.

Contribution

It provides a detailed comparison of dipole moments in different coordinate systems and clarifies the origin of isotopomeric differences through combined analytical and computational approaches.

Findings

Dipole moments vary depending on the coordinate system used.

Isotopic substitution affects dipole moment values.

Analytical and ab initio calculations agree on the origin of differences.

Abstract

Dipole moment functions of isotopomeric molecular ions, HCl+ and DCl+, are considered in the two coordinate systems, center of mass of nuclei and center of nuclear charges, both through simple analytical derivations and ab initio calculations of electronic structure at various interatomic separations. An origin of the different values for dipole moments of the isotopomers is discussed and demonstrated by the calculation data.