Calculation of the magnetic hyperfine structure constant of alkali metals and alkaline-earth-metal ions using the relativistic coupled-cluster method
AbstractThe Z-vector method in the relativistic coupled-cluster framework is used to calculate the magnetic hyperfine structure constant (AJ) of alkali metals and singly charged alkaline earth metals in their ground state electronic configuration. The Z-vector results are in very good agreement with the experiment. The AJ values of Li, Na, K, Rb, Cs, Be+, Mg+, Ca+, and Sr+ obtained in the Z-vector method are compared with the extended coupled-cluster results taken from Phys. Rev. A 91, 022512 (2015)PLRAAN1050-294710.1103/PhysRevA.91.022512. The same basis and cutoff are used for the comparison purpose. The comparison shows that the Z-vector method with the single and double approximation can produce a more precise wave function in the nuclear region than the ECC method.