5.8 HION Input

Several input files are required for the time-dependent treatment of hydrogen ionization. Currently, they need to be stored in the same input directory as specified with the parameter hion_datapath. There are four input files:

• model atom: The following formatting rules apply. Currently we only provide a hydrogen atom file H_6-2.atom. The module might be extended for other species in a future version.
• electron density look-up table (edens.dat) as function of total number density of hydrogen in cm$^{-3}$ or $m^{-3}$, gas temperature in K, and ionization degree of hydrogen.
• chemical abundances (abundance.input)
• partition functions (pf_kurucz.dat)

The first two files are always needed, whereas the files containing chemical abundances and partition functions are required the initial LTE electron densities for very first time step of a model sequence (and for creating electron density tables). Once the first time step has been calculated the last two input files are obsolete. We plan to implement another initial guess for the LTE densities so that only the model atom and the electron density look-up table are necessary.

Refer to [Leenaarts & Wedemeyer-Böhm (2005)] for more details.