Electron collisional excitation of NiXII

We used the intermediate-coupling frame transformation method. We compare predicted and observed line intensities using laboratory and solar spectra, finding good agreement for all the main soft X-ray lines.

With the exception of the three strongest transitions, large discrepancies with previous estimates are found, especially for the decays from the lowest 3s2 3p4 3d levels. This includes the forbidden UV lines. The atomic data for the n = 4 levels are the first to be calculated.