PHREEQC Identifiers
-m
-m0
-parms
-runge_kutta
-step_divide
-steps
-tol
-analytical_expression A1 A2 A3 A4 A5
Indicates the coefficients for an analytical expression of the temperature dependence of the mass action constant.
A1 A2 A3 A4 A5 - Coefficients of the analytical expression.
where T is temperature in Kelvin.,
Alternatives: analytical_expression, a_e, ae, -a
Indicates the number of times the ordinary differential equation method (Runge-Kutta or CVODE) is invoked to integrate a set of rate equations over a time interval.
Number Value indicating the number of times. Default is 500.
Indicates that the pH, pe or element concentration of this line is adjusted to achieve charge balance. Charge can only be used once in a SOLUTION definition.
Indicates whether or not the CVODE ordinary differential solver is used instead of the Runge-Kutta solver. CVODE might work better in case of stiff rate equations (large difference in kinetic rates).
option True or false. Default is false.
Indicates the number of terms in an extrapolation using the BFD method .
order Value indicating the number of terms. Value must be an integer between 1 and 5. Default is 5.
Indicates the maximum number of steps during one invocation of CVODE.
steps Value indicating the maximum number of steps. Default is 100.
Indicates the Davies equation is used to calculate the activity correction coefficient. For an exchange species: if –gamma or -davies is not given for an exchange species, the activity of the species is equivalent to its equivalent fraction; otherwise the Davies equation is used to calculate the activity correction coefficient which is multiplied by the equivalent fraction.
Alternatives: -d, davies
Indicates the enthalpy of a reaction which is used in van 't Hoff equation to determine the temperature dependence of the mass action constant.
Enthalpy Enthalpy of reaction at 25ºC. Default is 0.0.
Units Units may be calories, kilocalories, joules or kilojoules per mole (only energy unit needed). Default is kilojoules per mole.
Alternatives: -delta_h, deltah, -d
Indicates the density of the solution
density Density of the solution (kg/l). Default is 1.0.
Indicates the end of a BASIC program.
Indicates that an exchange site assemblages will be brought in equilibrium with a given solution composition.
Number Solution number indicating the solution with which the exchange site assemblage is equilibrated with.
Alternatives: equil, equilibrate, -e
-formula list of formula [stoichiometric coefficient]
Indicates a list of phases or chemical formula to be added by the kinetic reaction. In case of phase name is used defined in the PHASES data block, the formula of the phase is used.
list of formula Phase of chemical formula to be added by the kinetic reaction. The chemical formula must start with a capital letter and contain element symbols and stoichiometric coefficients. Each formula must be a charged-balanced combination of elements, except for defining exchangers or surfaces related to kinetics).
stoichiometric coefficient Defines the mole transfer coefficient for formula per mole of reaction progress calculated with the rate expressions in RATES. The mole transfer for formula relative to the aqueous phase is the product of the stoichiometric coefficient with the value of the reaction progress. If this value is negative (i.e. a negative mole transfer), reactants formula are removed from the solution. If the mole transfer is positive, reactions are added to the solution. Default is 1.
Alternatives: formula, -f
-gamma Debye-Hückel a Debye-Hückel b
Indicates parameters to calculate the activity correction coefficient.
Debye-Hückel a Parameter aº in the WATEQ equation
Debye-Hückel b Parameter b in the WATEQ equation
Alternatives: –g
-isotope name value [uncertainty limit]
Only used in inverse modelling. For more information, see Parkhurst and Appelo (1999).
Indicates the mass action constant K of the reaction equation.
log K log10 of K at 25ºC. Default is 0.0
For an exchange species: log K is implicitly relative to a single exchange species. This reference species typically have a value of 0.0. Note that the master exchange species also have a value of 0.0.
Alternatives: -log_k, logk, -l
Indicates the stoichiometry of the species to be used in the mole-balance equations. –mole_balance is used together with –no_check.
formula Formula of the species defining the stoichiometry to be used in the mole-balance equation
Alternatives: mole_balance, mass_balance, mb, -m, -mass_balance
Indicates the reaction is not checked for charge and elemental balance (by default, all reactions are checked). –mole_balance is needed to identify the formula of the species to be included in the mole-balance equations.
Alternatives: no_check, -n
pe pe [charge or phase name [saturation index]]
Indicates the pe of the initial or boundary solution.
pe pe value. Default is 4.
charge The pe is adjusted to achieve charge balance (not recommended)
phase name The pe is adjusted to achieve the saturation index of the specified phase
saturation index The pe is adjusted to this saturation index of the specified phase name
pH pH [charge or phase name [saturation index]]
Indicates the pH of the initial or boundary solution.
pH p H value. Default is 7.
charge The pH is adjusted to achieve charge balance
phase name The pH is adjusted to achieve the saturation index of the specified phase
saturation index The pH is adjusted to this saturation index of the specified phase name
Indicates the redox couple which is used to calculate the pe.
redox_couple Redox couple which defines pe. A redox couple is specified by two valence states of an element separated by a /.
Alternatives: -r
Indicates the beginning of a BASIC program.
Indicates the temperature.
Temperature Temperature in ºC. Default is 25ºC.
Alternatives: temperature, -t
Indicates the default concentration units
Concentration_unit Default concentration units. Default is mmol/kg water
Three groups of units are possible:
1. per liter water : /L
2. per kilogram water: /kgw
3. per kilogram solution: /kgs
Within a single solution definition, all concentrations must be within one group.
Mass can be expressed in mass units (as gram, or with prefix m for milligram or u for microgram) or in mole units (as mole, or with prefix m for milligram or u for microgram). For the group /kgs, parts per thousand (ppt), parts per million (ppm) or parts per billion (ppb) can be used.
Allowable units are thus:
Group 1 (\L) Group 2 (\kgw) Group 3 (\kgs)
g/l g/kgw g/kgs
mg/l mg/kgw mg/kgs
ug/l ug/kgw ug/kgs
mol/l mol/kgw mol/kgs
mmol/l mmol/kgw mmol/kgs
umol/l umol/kgw umol/kgs
ppt
ppm
ppb
Alternatives: -u
Indicates the mass of water of the solution. When the solution number corresponds to a solution composition defined as initial or boundary solution composition, the mass of water should be equal to 1 kg. The HP1 code adapts this mass of water to the initial water content at the different nodes.
Water_mass Mass of water in the solution (kg). Default is 1 kg.
Alternatives: -w