The number densities of the chemical species must be provided
as cell-centred quantities
cm (see Sect. 3.6).
The array (UIO) headers must be named following this
example: "Number density of H2".
The chemistry input file contains all data for the reaction network. It is a text file with a strict format following the UMIST 99 ratefile standard:
|2-4||reactants (max. 3 symbols with 8 characters)||3(A8,1X)|
|5-8||products (max. 4 symbols, first two with||2(A8,1X),2(1X,A4)|
|8 characters, last 2 with 4 characters||2(A8,1X),2(1X,A4)|
The symbols are usually the chemical symbols of the involved species,
e.g. C for carbon. The present species are recognised automatically.
Molecules consisting of more than one atom of the
same chemical element, e.g. H, are also possible (
A special case is the representative metal
M which is a
catalytic element only, i.e. it must appear as reactant and product.
The special symbol
PHOTON represents a photon as reaction product.
Currently no photon can be used as reactant ionising or exciting another species.
The reaction coefficients are needed to calculate the chemical rates
at runtime. The basic rate is then given by
An input file could look like this:
Refer to [Wedemeyer-Böhm et al. (2005)] for more details.