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The high-lying vibrational states of the magnesium dimer (Mg 2 ), which has been recognized as an important system in studies of ultracold and collisional phenomena, have eluded experimental characterization for half a century. Until now, only the first 14 vibrational states of Mg 2 have been experimentally resolved, although it has been suggested that the ground-state potential may support five additional levels. Here, we present highly accurate ab initio potential energy curves based on state-of-the-art coupled-cluster and full configuration interaction computations for the ground and excited electronic states involved in the experimental investigations of Mg 2 . Our ground-state potential unambiguously confirms the existence of 19 vibrational levels, with ~1 cm −1 root mean square deviation between the calculated rovibrational term values and the available experimental and experimentally derived data. Our computations reproduce the latest laser-induced fluorescence spectrum and provide guidance for the experimental detection of the previously unresolved vibrational levels.
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This content will become publicly available on July 21, 2026
Experimental and theoretical study of highly excited states of the cesium dimer
In this work, we report the results of a combined ab initio and experimental investigation of highly excited Σg+1 and Πg1 states of the cesium dimer in a previously unobserved energy region of the molecule. The structure of these high-lying electronic states was predicted via calculations in the framework of the pseudopotential method and observed via the optical–optical double resonance technique. Understanding the rovibronic structure of the cesium dimer at this high energy regime has significance for the formation of ultracold Cs2 ground state molecules and their detection using resonantly enhanced multiphoton ionization (REMPI) techniques. Using the ab initio results and the selection rules for dipole allowed transitions, the experimentally observed rovibrational levels were identified as belonging to the 11Σg+1 and 61Πg electronic states. The Dunham–RKR method was utilized to generate experimental potential energy curves for the two electronic states.
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- Award ID(s):
- 2207665
- PAR ID:
- 10617721
- Publisher / Repository:
- AIP
- Date Published:
- Journal Name:
- The Journal of Chemical Physics
- Volume:
- 163
- Issue:
- 3
- ISSN:
- 0021-9606
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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