collisional ionization rate coefficients update
Dere A&A 466, 771, here http://www.aanda.org/index.php?option=article&access=bibcode&bibcode=2007A%2526A...466..771DPDF has complete revision of rate coefficients for collisional ionization. The data are on line here http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=J/A+A/466/771
compare ionization distribution with 2006ApJS..167..343B