Reexamination of nuclear quadrupole moments in 39-41K isotopes

Nuclear quadrupole moments (Q's) in three isotopes of the potassium atom (K) with mass numbers 39, 40, and 41 are evaluated more precisely in this work. The Q value of K-39 is determined to be 0.0614(6) b by combining the available experimental result of the electric quadrupole hyperfine structure constant (B) with our calculated B / Q result of its 4P(3/2) state. Furthermore, combining this Q value with the measured ratios Q(K-40)/ Q(K-39) and Q(K-41)/ Q(K-39), we obtain Q(K-40)= -0.0764(8) b and Q(K-41)= 0.0747(7) b, respectively. These results disagree with the sub-1% accuracy standard values recently quoted by Pyykko [ Mol. Phys. 106, 1965 (2008)]. The calculations were carried out by employing the relativistic coupled-cluster theory at the single, double, and involving important valence triple approximation. The accuracies of the calculated B / Q results can be viewed on the basis of comparison between our calculated magnetic dipole hyperfine structure constants (A's) with their corresponding measurements for many low-lying states. Both A and B results in a few more excited states are presented. Also, we find that the latest reported experimental hyperfine structure constant results for the 4P states in K-39 are inconsistent with our calculations.