The ${}^{2}S$ and ${}^{2}D$ photoionization cross section (PICS) of lithium from the ${1s}^{2}2p$ state is calculated for photon energies below the ${\mathrm{Li}}^{+}$ $1s2s{}^{1}S$ threshold. Forty-seven resonances are predicted. All the important PICS peaks predicted are found to be associated with the spectral lines observed in the high precision experiment. Although the agreement between theory and experiment is excellent in most cases, there are some interesting exceptions. The possible sources of these discrepancies are discussed. An important discrepancy in the earlier experiments is resolved. Several new identifications are made. Some of the observed lines are reassigned.

• Received 27 October 1997

DOI:https://doi.org/10.1103/PhysRevA.57.3518