Dipole transitions in the bound rotational-vibrational spectrum of the heteronuclear molecular ion HD$^+$

Abstract

The non-relativistic three-body Schr\"odinger equation of the heteronuclear molecular ion HD$^+$ is solved in perimetric coordinates using the Lagrange-mesh method. Energies and wave functions of the four lowest vibrational bound or quasibound states $v=0-3$ are calculated for total orbital momenta from 0 to 47. Energies are given with an accuracy from about 12 digits for the lowest vibrational level to at least 9 digits for the third vibrational excited level. With a simple calculation using the corresponding wave functions, accurate dipole transition probabilities per time unit between those levels are given over the whole $v=0-3$ rotational bands. Results are presented with six significant figures.