Transition probability ratios for selected multiplets of C I, N I, and O I, and comparisons with recent calculations

With a wall-stabilized high-current arc, we have measured the transition probabilities of several multiplet pairs of C I, N I, and O I. Pairs have been selected for which two recent ab initio calculations have produced widely different results. All chosen multiplets are among the prominent, strong features of their respective spectra, and the pairing is in each case done for multiplets that hardly differ in their excitation energies. Our results do not favor either of the calculations, but are consistent with an earlier experiment.