Lithium hyperfine splitting

We present an approach for the calculation of relativistic mα⁶ corrections to the lithium ground-state hyperfine splitting. It is based on the effective Hamiltonian derived from relativistic quantum electrodynamic theory. This approach with the help of appropriate nonrelativistic correlated basis sets has the potential to be more accurate than currently available relativistic computational methods such as the relativistic many-body perturbation theory, configuration interaction, or multiconfiguration Dirac-Fock method.