Photodetachment of the 2${\mathit{p}}^2$${(}^3$${\mathit{P}}^{\mathit{e}}$) state of ${\mathrm{H}}^{\mathrm{-}}$

Results of semiempirical, adiabatic hyperspherical calculations are presented for the photodetachment cross section of the process ${\mathrm{H}}^{\mathrm{-}}$ 2${\mathit{p}}^2$${(}^3$${\mathit{P}}^{\mathit{e}}$)+γ→H(n=2)+${\mathit{e}}^{\mathrm{-}}$ at photon energies in the range from threshold to 0.125 a.u. above. We find the detachment cross section to have a maximum value of 482 Mb at 25.7 meV above threshold, in good agreement with results of close-coupling calculations by Jacobs, Bhatia, and Temkin [Astrophys. J. 242, 1278 (1980)]. In contrast to the close-coupling results, however, we find that the detachment cross section rises by a factor of more than 400 from its threshold value to its maximum.