Charge transfer 1 Cosmology 1 Galaxies 1 H ii region 1 H ii regions 1 Hydrodynamics 1 ISM: abundance 1 ISM: abundances 1 Ionization of gases 1 Ionization state 1 Metal cooling 1 Metal line 1 Metals 1 Metals chemistry Method: numerical 1 Non equilibrium 1 Numerical methods 1 Photoionization 1 Radiation hydrodynamics 1 Radiative transfer 1 Red Shift 1 Red shift 1 hydrodynamics 1 methods: numerical 1 radiative transfer 1