On the Quadrupole Moment of the Hydrogen Molecule

Abstract
Various matrix elements of the quadrupole moment of H2 in the ground electronic state are calculated in the adiabatic approximation and the results are presented in Table II. These matrix elements are of the form <vJ | Q | v′J′>, where v, J and v′, J′ denote the vibrational and rotational quantum numbers of the initial and final states, respectively; Q represents the quadrupole moment for fixed nuclei. The calculations are based on the adiabatic potential and electronic quadrupole moment computed by Koℏos and Wolniewicz. The results of the calculations are compared with experimental values obtained from the quadrupole absorption spectrum by Fink, Wiggins, and Rank. The influence of the rotation—vibration interaction on the matrix elements is discussed and an estimate of the contribution due to nonadiabatic effects is given for the case Δv=0.