Ab initio calculations of the hyperfine structure of 109Cd, 109Cd+ and reevaluation of the nuclear quadrupole moment Q(109Cd)
Abstract
Large scale ab initio calculations of the electric contribution (i.e. the electric field gradient) to the electric quadrupole hyperfine interaction constants B for the 5p~2P3/2 state in 109Cd+ ion and the 5s5p~3P1,2 states in neutral 109Cd atom were performed. To probe the sensitivity of B to different electron correlation effects, six sets of variational multi-configuration Dirac-Hartree-Fock and relativistic configuration interaction calculations employing different strategies were carried out. The calculated electric field gradients, together with experimental values of B, allow us to extract a new value of the nuclear electric quadrupole moment Q(109Cd) = 0.634(22) b which is about 5\% larger than the recommended value [Stone, At. Data Nucl. Data Tables 111-112, 1 (2016); Pyykk\"o, Mol. Phys. 116, 1328 (2018)]. Efforts were made to provide a realistic theoretical uncertainty for the final Q value based on statistical principles and correlation with the magnetic dipole hyperfine interaction constant A.