THE QUARTET LEVELS OF LITHIUM

We studied the Is2snl and 1s2pnl(l less than or equal to 4) quartet st ates of the lithium atom by a model-potential method with B-spline bas is functions in the CI scheme. The transition wavelengths and probabil ities, and lifetimes for electric dipole decay are calculated and comp ared with experimental and other theoretical results. A large number o f transitions, which can possibly be observed, are presented. Our calc ulated transition wavelengths and lifetimes are in good agreement with the available experimental results. Including relativistic, radiative , and mass-polarization corrections for 1s2p P-3 and 1s2s S-3 Li+ core s, we calculated lambda(air) for 1s2snl-1s2pnl transitions. Some of th ese agreed with experimental results within 1 Angstrom. The lifetime o f [1s2p3s] P-4 degrees is calculated to be 9.89 ns, which is the best agreement with the experimental result, 10.1 +/- 0.4 ns, among the pre sent theoretical results. The lifetime of [1s2s3s] S-4 is also improve d.