Absolute photoionization cross sections of atomic oxygen

Abstract
The absolute values of the photoionization cross sections of atomic oxygen have been measured from the ionization threshold to 120 Å. An autoionizing resonance belonging to the 2s2p4(4P)3p(3Do, So3,3Po) transition has been observed at 479.43 Å; and another line, at 389.97 Å. However, although the experimental data are in excellent overall agreement with rigorous close-coupling calculations, which include electron correlations in both the initial final states, there are discrepancies near threshold that may be significant.