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arXiv:2301.11307 · Physical Review A

Ab initio potential-energy curves, scattering lengths, and rovibrational levels of the He2+ molecular ion in excited electronic states

Jacek Gȩbala, Michał Przybytek, Marcin Gronowski, Michał Tomza

Published Nov 21, 2023• 7 citations
arXivHTMLPDF

Abstract

We calculate accurate potential-energy curves for a ground-state ${\mathrm{He}}^{+}$ 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 ${\mathrm{He}}_{2}^{+}$ 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 ${\mathrm{He}}_{2}^{+}$ molecular ion in the excited electronic state and collisional studies of ${\mathrm{He}}^{+}$ ions immersed in ultracold gases of metastable He atoms.

DOI
10.1103/physreva.108.052821

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