Ab initiostudy of electronic states and radiative properties of the AcF molecule

Abstract

Relativistic coupled-cluster calculations of the ionization potential, dissociation energy, and excited electronic states under 35 000 cm−1 are presented for the actinium monofluoride (AcF) molecule. The ionization potential is calculated to be IPe = 48 866 cm−1, and the ground state is confirmed to be a closed-shell singlet and thus strongly sensitive to the T,P-violating nuclear Schiff moment of the Ac nucleus. Radiative properties and transition dipole moments from the ground state are identified for several excited states, achieving a mean uncertainty estimate of ∼450 cm−1 for the excitation energies. For higher-lying states that are not directly accessible from the ground state, possible two-step excitation pathways are proposed. The calculated branching ratios and Franck–Condon factors are used to investigate the suitability of AcF for direct laser cooling. The lifetime of the metastable (1)3Δ1 state, which can be used in experimental searches of the electric dipole moment of the electron, is estimated to be of order 1 ms.

Experimental perspectives on the matter–antimatter asymmetry puzzle: developments in electron EDM and H¯ experiments

“…As a ground-breaking example of these innovative processes, the successful formation and identification of molecules containing Ra isotopes in an ion trap [33] as well as the first spectroscopy of radium monofluoride (RaF) molecules [34,35] have been the starting whistle for experimental work with radioactive molecules. While the general perspective of this newly emerging field is summarized in [22], molecules which have been proposed in the context of EDM searches are for instance RaF [34,36,37], RaOH [38,39], RaO [40], RaH [41], normalRaOCH3+ [33,42], AcF [43] or short-lived ThO [44], as well as normalThOH+, normalThF+ [44] or normalAcO+ [45].…”