Calculations of vibration-rotation energy levels ofHD+

An artificial-channels scattering method [M. Shapiro and G. G. Balint-Kurti, J. Chem. Phys. 71, 1461 (1979)] is used with a transformed Hamiltonian [R. E. Moss and I. A. Sadler, Molec. Phys. 66, 591 (1989)] to calculate the energies of vibration-rotation levels for the ground electronic state of ${\mathrm{HD}}^{+}$. All nonadiabatic effects, except for part of the coupling of rotational and electronic angular momenta, are accounted for. The results, which are for v=0–21, J=0,1, together with some other levels involved in observed transitions, are compared with previous calculations, particularly those of Wolniewicz and Poll [Molec. Phys. 59, 953 (1986)]. Inclusion of a correction to the energies of J≠0 levels to allow for the remaining contribution of Π electronic states permits comparison with experimental transition energies. The agreement is excellent.