Ab initio potential energy curves, scattering lengths, and rovibrational levels of the He${}_2^{+}$ molecular ion in excited electronic states

Abstract

We calculate accurate potential energy curves for a ground-state He${}^{+}$ ion interacting with a He atom in the lowest-energy metastable ${}^{3}S$ electronic state. We employ the full configuration interaction method, equivalent to exact diagonalization, with results extrapolated to the complete basis set limit. The leading relativistic and adiabatic corrections are included using perturbation theory. We calculate rovibrational levels and spectroscopic constants of the He${}_2^{+}$ molecular ion in excited electronic states for three stable isotopologues. We predict the scattering lengths for ultracold ion-atom collisions. The theoretical data are presented with their uncertainties and agree well with previous results for the ground state. The reported results may be useful for the spectroscopy of the He${}_2^{+}$ molecular ion in the excited electronic state and collisional studies of He${}^{+}$ ions immersed in ultracold gases of metastable He atoms.

18 pages, 6 figures, 7 tables

References in corpus (9)

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• Nonadiabatic corrections to the wave function and energy
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• Precision Measurements in Few-Electron Molecules: The Ionization Energy of Metastable ${}^4$He${}_2$ and the First Rotational Interval of ${}^4$He${{}_2}^{+}$
• Quantum-Logic Detection of Chemical Reactions
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Cited by in corpus (5)

• Diatomic molecules of alkali-metal and alkaline-earth-metal atoms: interaction potentials, dipole moments, and polarizabilities
• Estimating complete basis set extrapolation error through random walk
• Characterization of the electronic ground state of He${}_2^{+}$ by high-resolution photoelectron spectroscopy
• Rovibrational computations for He${}_2^{+}$ X ${\Sigma }_{\mathrm{u}}^{+}$ including non-adiabatic, relativistic and QED corrections
• Interactions and cold collisions of AlF in the ground and excited electronic states with He