Single- and Multiphoton Infrared Laser Spectroscopy of Sb - : A Case Study

A combination of single- and multiphoton tunable infrared laser experiments is utilized to accurately and conclusively determine the bound terms and fine structure of ${\mathrm{Sb}}^{\ensuremath{-}}({5p}^{4})$. The ${}^{3}{P}_{2}$ binding energy is determined to be 8447.86(15) ${\mathrm{cm}}^{\ensuremath{-}1}$ (electron affinity of antimony) and the previously unobserved ${}^{3}{P}_{1}$, ${}^{3}{P}_{0}$, and ${}^{1}{D}_{2}$ levels are found at 2684.37(15), 2800.8(6), and 7392.55(15) ${\mathrm{cm}}^{\ensuremath{-}1}$ above the ${}^{3}{P}_{2}$ ground level, respectively. Relativistic configuration interaction calculations predict these splittings to be 2516, 2831, and 7628 ${\mathrm{cm}}^{\ensuremath{-}1}$. Widths and shapes of resonances observed in two-photon detachment yields are modeled on the basis of calculated hyperfine structure constants.