Autodetachment States ofO−

A configuration-interaction study of doublet autodetaching states of ${\mathrm{O}}^{-}$ has predicted the following levels: ${\mathrm{O}}^{-}\left[2\mathrm{}{p}^3\right({}_{}{}^4{}_{}{}^{}S_{}^0{}_{}{}^{}\left)3s3p\right({}_{}{}^2{}_{}{}^{}P\left)\right]$ at 9.50 eV, ${\mathrm{O}}^{-}\left[2\mathrm{}{p}^3\right({}_{}{}^2{}_{}{}^{}D_{}^0{}_{}{}^{}\left)3\mathrm{}{s}^2\right({}_{}{}^2{}_{}{}^{}D_{}^0{}_{}{}^{}\left)\right]$ at 12.05 eV, and ${\mathrm{O}}^{-}\left[2\mathrm{}{p}^3\right({}_{}{}^2{}_{}{}^{}P_{}^0{}_{}{}^{}\left)3\mathrm{}{s}^2\right({}_{}{}^2{}_{}{}^{}P_{}^0{}_{}{}^{}\left)\right]$ at 13.65 eV. These states can explain most of the structure, which results from collisions of the ground-state ${\mathrm{O}}^{-}$ ion with rare-gas atoms, as found by Edwards, Risley, and Geballe. An additional level ${\mathrm{O}}^{-}\left[2\mathrm{}{p}^3\right({}_{}{}^4{}_{}{}^{}S_{}^0{}_{}{}^{}\left)3\mathrm{}{p}^2\right({}_{}{}^2{}_{}{}^{}P_{}^0{}_{}{}^{}\left)\right]$ at 10.87 eV is found which has not yet been detected experimentally. The present formalism computes eigenvalues of $H_{\mathrm{QQ}}$ using a fixed ${\mathrm{O}}^{+}$ core with configuration mixing of states of the outer two active electrons. The shift contribution to the resonance energy is neglected.