Calculations on the hyperfine constants of the ground states for lithium-like system

In this paper a relativistic many-body perturbation calculation is performed to calculate the hyperfine constants of the ground states for lithium-like isoelectronic sequence. Zeroth-order hyperfine constants are calculated with Dirac--Fock wavefunctions, and the finite basis sets of the Dirac--Fock equations are constructed by B splines. With the finite basis sets, the core polarization and the correlation effect are evaluated.