The simulations have a horizontal resolution of 12 and a
vertical resolution of 6-24 km.  The physical dimensions are 12x12
Mm wide.  The simulation goes from the temperature miminmum do a
depth of 6 Mm below the visible surface.

The simulation was started with a horizontal resolution of 12 km
and a weak uniform vertical field of 10 G, which was slowly increased
with an efolding time of 2 hours until the average vertical field
became 60 G.

Stokes spectra are calculatied only for every other pixel.  Stokes
spectra i,q,u,v are stored in separate file 'mhd12_6km_232.0.prf'
as an array [wavelength,0-3,x,y] with dimensions [200,4,1008,1008].
They are normalized to the HSRA continuum.  They can be read with
the IDL function read_prf.pro.  The wavelength array is included
in the sturcture.  The atmosphere data is stored in two files
mhd12_6km_232.0.lil This can be read with the idl procedure
read_lil.pro.