Two-photon detachment of H-

This is the published version, also available here: http://dx.doi.org/10.1103/PhysRevA.61.060702.A precision calculation of the two-photon detachment cross section for H- is performed by means of a non-Hermitian Floquet theory. A highly accurate initial state wave function is used along with fully correlated saddle-point wave functions for the intermediate and final states. The cross section is investigated for energies below the n=2 and n=3 thresholds. The peak cross section predicted for the 1D resonance is 3.10×10-49 cm4 sec at 10.873 2 eV. It represents an ab initio theoretical prediction in complete agreement with the experimental result of 3.2 (+1.8,-1.2)×10-49 cm4 sec at 10.873 2(27) eV