Ground and excited states of Li−, Be− through a density-based approach

Density functional theory (DFT)-based calculations are performed for ground [He]2s2 1Se, and three metastable bound excited states, 1s2s2p2 5Pe, 1s2p3 5So, 1s2s2p3p 5Pe of Li− and [He]2s2p2 4Pe, [He]2p3 4So, 1s2s2p3 6So of Be− each. The Kohn–Sham equation is solved by generalized pseudospectral method using the work-function-based exchange and Lee–Yang–Parr correlation potential. Total energies (E), radial densities, selected density moments and two transition wavelengths (λ) (1s2s2p2 5Pe → 1s2p3 5So of Li−, [He]2s2p2 4Pe → [He]2p3 4So of Be−) show reasonably good agreement with available theoretical and experimental data. Absolute deviations in E are within 0.007–0.171%, while λ of Li− and Be− deviate by 0.891% and 0.438% of the experimental values. This offers a simple practical route towards accurate reliable calculation of excited states of anions within DFT.