Photoionization of lithium below the Li⁺ 1s2s³S threshold

A saddle-point complex-rotation method is used to calculate the resonance energy, width, and photoionization cross section (PICS) of lithium below the Li⁺ 1s2s³S threshold. Fourteen ²P^o resonances are studied. These results are compared with the most precise experimental data in the literature. Most of the Auger widths of these resonances are extremely narrow, which makes a direct theory-experiment PICS comparison difficult. However, if we convolute the predicted cross section with a Gaussian profile using the experimental resolution for full width at half maximum, the resulting profile agrees closely with the high-resolution photoion measurement.