Adiabatic values for a selection of energy levels and matrix elements of the quadrupole moment and the polarizability of H2, HD, D2, HT, DT, and T2 are presented. Additional energy levels and matrix elements are available for a minimal charge upon request from the Depository of Unpublished Data, C.I.S.T.I., National Research Council of Canada, Ottawa, Ont., Canada K1A 0S2.

We present an improved adiabatic calculation of the quadrupole moment of the H2 molecule and of its matrix elements between various vibrational rotational states. Particular attention is paid to making a reasonable estimate of the accuracy of transition elements between widely different vibrational states. An order of magnitude estimate of the nonadiabatic contribution to the quadrupole moment is also given and we show that it is typically of the order of a tenth of a percent of the adiabatic value.

The Hamiltonian describing the rotation and vibration of a homonuclear diatomic molecule in the field of a point charge at a fixed distance from its centre-of-mass is given. Numerical results for the Stark shift of the molecular levels due to a point charge of either sign are listed for H2, D2, and T2 as a function of the separation of the point charge from the molecule. The intensity associated with transitions between perturbed levels is discussed briefly.

No abstract

On the quadrupole moment of the hydrogen molecule in excited statesVarious 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 thewhere 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 Kolos 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 ",v = O.