Valence photodetachment of Li^- and Na^- using relativistic many-body techniques

The multiconfiguration Tamm-Dancoff technique (MCTD) is applied to study photodetachment of negative ions of lithium and sodium. A cusplike structure is found in the photodetachment cross section just below the first detachment-plus-excitation threshold of Li- (Li 2p), and of Na - (Na 3p), in qualitative agreement with existing theoretical and experimental results. The current work emphasizes the importance of correlation in the form of configuration interaction in the photodetachment process and demonstrates the utility of MCTD in dealing with highly correlated systems. © 2011 American Physical Society.