The energy levels of C + doublet bound states with , were calculated using the R-matrix method. Photoionization cross-sections for these states were computed using a variable step energy mesh ensuring the correct mapping of resonances. The importance of correctly delineating the autoionizing resonances in the photoionization cross-sections was demonstrated by considering the area under the cross-section. In the case of 2s2p2 2D, this area differs by factor of 3 comparing our data with those from the OP (Yu Yan & Seaton ).
We find that moving the two energetically lowest resonances to the experimental positions in the appropriate cross-sections significantly increases their contribution to the recombination coefficients, particularly at low temperatures.
The effective recombination coefficients for lines of C II have been tabulated in the temperature range K and at electron density Ne = 104 cm-3. The use of atomic data of high quality for bound-bound and bound-free radiative processes among all the terms with means that the results given here are expected to be more reliable than any previous work.
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