Abstract
Excitation energies of the , , , and ( and ) in Sr ii are evaluated. First-order, second-order, third-order, and all-order Coulomb energies and first-order and second-order Coulomb-Breit energies are calculated. Reduced matrix elements, oscillator strengths, transition rates, and lifetimes are determined for the levels up to . Electric-dipole (, ), electric-quadrupole (, ), and electric-octupole (, ) matrix elements are calculated to obtain the ground-state , , and static polarizabilities. Scalar and tensor polarizabilities for the and excited states in Sr ii are also calculated. All the above-mentioned matrix elements are determined using the all-order method. We also investigate the hyperfine structure in . The hyperfine values and values are determined for the first low-lying levels up to . The quadratic Stark effect on hyperfine-structure levels of the ground state is investigated. The calculated shift for the transition is found to be 0.120(1) Hz/(kV/cm). These calculations provide a theoretical benchmark for comparison with the experiment and theory. A careful study of uncertainty of our calculations is carried out for the transition-matrix elements, line strengths, transition rates, lifetimes, polarizabilities, and the Stark shift coefficient.
- Received 18 June 2010
DOI:https://doi.org/10.1103/PhysRevA.82.022504
©2010 American Physical Society