Required Cards:

REACTION <string>

Reaction equation. The forward rate is applied to reaction quotient of species on left side of reaction. The reverse or backward rate is applied to the right side.

Optional Cards:

FORWARD_RATE <float>

rate constant for n^th^-order forward reaction [kg^(n-1)/mol^(n-1) -sec]

BACKWARD_RATE <float>

rate constant for n^th^-order reverse reaction [kg^(n-1)/mol^(n-1) -sec]

Examples:

GENERAL_REACTION
  REACTION Tracer <-> Tracer2
  FORWARD_RATE 1.7584d-7 ! half life at 0.125 y
  BACKWARD_RATE 0.d0
/

CHEMISTRY
  PRIMARY_SPECIES
    A(aq)
    B(aq)
    C(aq)
  /
  ...
  GENERAL_REACTION
    REACTION A(aq) <-> B(aq)
    ! Calculating forward rate from half-life
    ! forward rate = -ln(0.5) / half-life [1/sec]
    FORWARD_RATE 1.75836d-9  ! 1/s  half life = 12.5 yrs
    BACKWARD_RATE 0.d0
  /
  GENERAL_REACTION
    REACTION B(aq) <-> C(aq)
    FORWARD_RATE 8.7918d-10  ! 1/s  half life = 25. yrs
    BACKWARD_RATE 0.d0
  /
  GENERAL_REACTION
    ! Note that C(aq) simply decays with no daugher products
    REACTION C(aq) <->
    FORWARD_RATE 4.3959d-9  ! 1/s  half life = 5. yrs
    BACKWARD_RATE 0.d0
  /
  ...
/