As described below, the treatment of multiple electron ejection, which had followed @Weisheit1972, is now generalized to non-adjacent stages of ionization [@HenneyEtAl05]. Ionization and recombination coupling non-adjacent ion states can also be important in grain surface recombination.

This treatment is approximate at high densities and for temperatures which are a significant fraction of the ionization potential of a species. The use of summed recombination rate coefficients in effect assumes that all recombinations eventually populate the ground level. Ionization processes out of excited levels are neglected. Both are no longer true if the density is large enough for excited levels to play an important role. Expanding the treatment of these species to the approach now used for the H and He iso sequences is a high priority for future development.

Bound levels of each ion are treated with a variety of models. We are enhancing the code to use external databases as much as possible. We have the ability to read the Chianti atomic database[^3] [@Dere.K97CHIANTI---an-atomic-database-for-emission; @Landi2012] and this release of  includes Version 7.0. Chianti is used for most ions of Fe while for other species we mainly use our internally developed atomic database. @Lykins.M12Radiative-cooling-in-collisionally-and-photo shows that our original database, which 