Electron impact excitation of semi-forbidden transitions in O III

Abstract
Calculates the collision strengths for the transitions 1s22s22p23Pe to 1s22s2p35S0, 1s22s2p35S0 to 1s22s2p33D0 and 1s22s2p35S0 to 1s22s2p33P0 in O III using the R-matrix method. The transition 3Pe to 5S0 is of particular importance in diagnostic studies of densities in the quiet sun and in coronal holes. The authors include all channels with configurations 1s22s22p2, 1s22s2p and 1s22p4 in the expansion of the total wavefunction. They also include 3s, 3p and 3d pseudo-orbitals and allow for configuration interaction in all the included states, plus the correlation terms in the total wavefunction. Results are presented for collision strength and its average over a Maxwellian distribution over a wide temperature range and are compared with other work.