Ab initio study of electronic states and radiative properties of the AcF molecule

Leonid V Skripnikov; Alexander V Oleynichenko; Andréi Zaitsevskii; Nikolai S Mosyagin; Michail Athanasakis-Kaklamanakis; Mia Au; Gerda Neyens

doi:10.1063/5.0159888

Ab initio study of electronic states and radiative properties of the AcF molecule

J Chem Phys. 2023 Sep 28;159(12):124301. doi: 10.1063/5.0159888.

Authors

Leonid V Skripnikov^{1

2}, Alexander V Oleynichenko¹, Andréi Zaitsevskii^{1

3}, Nikolai S Mosyagin¹, Michail Athanasakis-Kaklamanakis^{4

5}, Mia Au⁶, Gerda Neyens⁵

Affiliations

¹ Petersburg Nuclear Physics Institute named by B. P. Konstantinov of National Research Center "Kurchatov Institute" (NRC "Kurchatov Institute" - PNPI), 1 Orlova roscha, Gatchina, 188300 Leningrad region, Russia.
² Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia.
³ Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie gory 1/3, Moscow 119991, Russia.
⁴ Experimental Physics Department, CERN, CH-1211 Geneva 23, Switzerland.
⁵ KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium.
⁶ Systems Department, CERN, CH-1211 Geneva 23, Switzerland.

PMID: 38127371
DOI: 10.1063/5.0159888

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.