2. Required inputs

Model density and composition

Grid parameters, cell densities and nuclear composition are stored in model.txt

Atomic data

• adata.txt stores atomic energy levels and ionisation potentials.
• compositiondata.txt sets a filter on the elements, ion stages, and energy levels that are included.
• transitiondata.txt stores A values and collision strengths of level to level transitions.
• phixs_data.txt stores photoionisation cross sections.

Nuclear data

Gamma decay spectra are stored in nuc_lines.txt files, e.h. ni56_lines.txt

Input parameters

input.txt hold several simulation parameters including the number of timesteps, and the start and end time in days. There are also settings for the number of pure LTE timesteps, and an optically-thick condition that switches cells to a grey opacity treatment.