Abstract
The excitation energies of , , , and states in neutral lithium are evaluated within the framework of relativistic many-body theory. First-, second-, third-, and all-order Coulomb energies and first- and second-order Breit corrections to energies are calculated. All-order calculations of reduced matrix elements, oscillator strengths, transition rates, and lifetimes are given for levels up to . Electric-dipole , electric-quadrupole , and electric-octupole , matrix elements are evaluated to obtain the corresponding ground-state multipole polarizabilities using the sum-over-states approach. Scalar and tensor polarizabilities for the and states are also calculated. Magnetic-dipole hyperfine constants are determined for low-lying levels up to . The quadratic Stark shift for the ground-state hyperfine transition is found to be , in slight disagreement with the experimental value . Matrix elements used in evaluating polarizabilities, hyperfine constants, and the quadratic Stark shift are obtained using the all-order method.
- Received 28 December 2007
DOI:https://doi.org/10.1103/PhysRevA.77.022510
©2008 American Physical Society