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PREFACTOR

Specifies coefficients for defining prefactors in mineral precipitation-dissolution reactions.

../../../_images/prefactor.jpg

Required Cards:

RATE_CONSTANT <float>
Kinetic rate constant [mol/m2/sec]. (See MINERAL_KINETICS)
PREFACTOR_SPECIES <string>
Name of prefactor species. Appears as subscripts j and i in above equation corresponding to primary and secondary species.

Optional Cards:

ACTIVATION_ENERGY <float>
Activation energy for rate constant \(k_{ml}\).
ALPHA <float>
\(\alpha_{jl}^m\) parameter in above equation.
BETA <float>
\(\beta_{jl}^m\) parameter in above equation.
ATTENUATION_COEF <float>
\(K_{jl}\) in above equation.

Examples (data from Palandri and Kharaka (2004))

CHEMISTRY
  ...
  MINERAL_KINETICS
    K-Feldspar
      PREFACTOR
        RATE_CONSTANT -12.41d0 mol/m^2-sec
        ACTIVATION_ENERGY 38.d0
      /
      PREFACTOR
        RATE_CONSTANT -10.06d0 mol/m^2-sec
        ACTIVATION_ENERGY 51.7d0
        PREFACTOR_SPECIES H+
          ALPHA 0.5d0
        /
      /
      PREFACTOR
        RATE_CONSTANT -21.20 mol/m^2-sec
        ACTIVATION_ENERGY 94.1d0
        PREFACTOR_SPECIES H+
          ALPHA -0.823d0
        /
      /
    /
  /
...
END