Fock-space relativistic coupled cluster study on the RaF molecule promising for the laser cooling

The potential energy curves of the ground and five low-lying excited terms of the RaF molecule are calculated using the Fock-space relativistic coupled theory. The electronic term energies, equilibrium inter nuclear distances, transition and permanent dipole moments, sequences of vibrational energies, harmonic vibrational frequencies, Franck-Condon factors, and radiative lifetimes are predicted. The calculated spectroscopic constants are in good agreement with the available theoretical and experimental data. The scheme for the direct laser cooling involving the first excited A(2)Pi(1/2) state is proposed. The data obtained in this study suggests the A(2)Pi(1/2) -> X-2 Sigma(+) channel in the RaF molecule is the almost ideal case for direct laser cooling. It is quite possible that the effective cooling scheme for the RaF molecule can be realized using only one pump laser. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The potential energy curves of the ground and five low-lying excited terms of the RaF molecule were calculated using the Fock-space relativistic coupled theory. Various spectroscopic constants were predicted and a scheme for direct laser cooling was proposed. The study suggests that the A(2)Pi(1/2) -> X-2 Sigma(+) channel in the RaF molecule is an almost ideal case for direct laser cooling.