Photoionization of the formyl radical using the B -spline R -matrix method

There are major discrepancies between recent [J. D. Savee et al., J. Phys. Chem. A 125, 3874 (2021)] and the two early [B. L. FitzPatrick et al., J. Chem. Phys. 133, 094306 (2010); V. A. Shubert and S. T. Pratt, J. Phys. Chem. A 114, 11238 (2010)] measurements regarding an absolute cross section for the photoionization of formyl radicals. To estimate the accuracy of the various results, we carried out calculations with the $R$-matrix method employing the configuration-interaction method to describe electronic correlation. The quality of the description of the continuum is assessed by using the Gaussian, $B$-spline, and their mixed bases. The convergence of the results is checked by changing the partial waves and active spaces. Accurate cross sections and asymmetry parameters for the valence orbitals are reported for photon energies from the ionization thresholds to 90 eV. Extensive resonance structures are observed near the ionization threshold.