Electron-impact ionization of C3+ using the R-matrix pseudo-state method

The time-independent R-matrix pseudo-state (RMPS) method is used to calculate the total electron-impact ionization cross section for C3+ In order to handle the large pseudo-state expansions included within the RMPS calculations, the (N + 1)-electron Hamiltonian for each LS pi symmetry is partitioned over the many processors of a distributed-memory parallel computer. A series of RMPS calculations were performed in order to study convergence as a function of the angular momentum of the pseudo-states. The RMPS cross sections were found to converge rapidly with angular momentum but are slightly lower than the cross sections obtained from a time-dependent close-coupling calculation and a time-independent distorted-wave calculation. However, all our non-perturbative and perturbative theoretical cross sections, as well as previous converged close-coupling cross sections, are significantly higher than cross sections obtained from crossed-beams experimental measurements.