Iron ionization and recombination rates and ionization equilibrium.
M. Arnaud & J. Raymond (1992, ApJ, 398, 394).

Fit parameters for iron radiative recombination rates.
Byte-per-byte description of file: ar1.dat (12 records)
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   Bytes Format  Units   Label        Explanations
-------------------------------------------------------------------------------
   1-  2  I2     ---     Z            Atomic number
   4-  5  I2     ---     N            Number of electrons
   7- 14  E8.2   cm^3/s  Ar           Fit parameter
  16- 20  F5.3   ---     a            Fit parameter
  21- 26  F6.4   ---     b            Fit parameter
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  /alpha = Ar*(T/10**4K)**[-a-b*log10(T/10**4K)] cm**3/s

Fit parameters for iron dielectronic recombination rates.
Byte-per-byte description of file: ar2.dat (25 records)
-------------------------------------------------------------------------------
   Bytes Format  Units   Label         Explanations
-------------------------------------------------------------------------------
   1-  2  I2     ---     Z             Atomic number
   4-  5  I2     ---     N             Number of electrons
   7- 15  E9.3   eV      E_1           Fit parameter
  17- 24  E8.2   eV      E_2           Fit parameter
  26- 33  E8.2   eV      E_3           Fit parameter
  35- 42  E8.2   eV      E_4           Fit parameter
  44- 51  E8.2   ---     c_1           Fit parameter
  53- 60  E8.2   ---     c_2           Fit parameter
  62- 69  E8.2   ---     c_3           Fit parameter
  71- 78  E8.2   ---     c_4           Fit parameter
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  /alpha = T**(-3/2)*Sum[c_i*exp(-E_i/kT)] cm**3/s