Solute names

It is necessary to label each solute component in several places within pytzer:

  1. In your input files, for data import using pytzer.io;

  2. In the ions variable that goes into the pytzer.model function;

  3. In the cfdict that defines the interaction coefficients;

  4. In the pytzer.props functions;

  5. In the names of the interaction coefficient functions in pytzer.coeffs.

The convention in pytzer is to just write out the chemical formula for the relevant ion, including internal stoichiometry (but not subscripted), and excluding charges. No brackets are used. The following tables list all of the names used for different solutes in the functions that are available by default in pytzer:

Elemental ions

The elemental ions are arranged in groups and listed in order of atomic number.

Each transition metal may have multiple possible oxidation states. These are indicated in the code with j for each positive charge and q for each negative: for example, iron(II) and iron(III) (Fe2+ and Fe3+) become Fejj and Fejjj respectively, while V1− would become Vq. The letters j and q are used to avoid confusion: they do not appear in the symbol for any element.

Solute name Formula Name in pytzer
Alkali metals
Hydrogen H+ H
Lithium Li+ Li
Sodium Na+ Na
Potassium K+ K
Rubidium Rb+ Rb
Caesium Cs+ Cs
Alkaline earth metals
Magnesium Mg2+ Mg
Calcium Ca2+ Ca
Strontium Sr2+ Sr
Barium Ba2+ Ba
Transition metals
Manganese(II) Mn2+ Mnjj
Iron(II) Fe2+ Fejj
Iron(III) Fe3+ Fejjj
Cobalt(II) Co2+ Cojj
Nickel(II) Ni2+ Nijj
Copper(II) Cu2+ Cujj
Post-transition metals
Zinc(II) Zn2+ Znjj
Cadmium(II) Cd2+ Cdjj
Halogens
Fluoride F− F
Chloride Cl− Cl
Iodide I− I
Lanthanides
Lanthanum La3+ La

Other ions

The other ions are listed approximately in order of the atomic number of their most interesting component.

Solute name Formula Name in pytzer
Borate B(OH)4− BOH4
Bicarbonate HCO3− HCO3
Carbonate CO32− CO3
TrisH+ (HOCH2)3CNH3+ trisH
Nitrate NO3− NO3
Hydroxide OH− OH
Dihydrogen phosphate H2PO4− H2PO4
Thiocyanate SCN− SCN
Bisulfate HSO4− HSO4
Sulfate SO42− SO4
Thiosulfate S2O32− S2O3
Chlorate ClO3− ClO3
Perchlorate ClO4− ClO4
Magnesium hydroxide MgOH+ MgOH
Ferrocyanide [Fe(CN)6]4− FejjCN6
Ferricyanide [Fe(CN)6]3− FejjjCN6
Bromate BrO3− BrO3
Iodate IO3− IO3
Uranyl UO22+ UO2

Neutral species

Neutral species are referred to as ions throughout pytzer, for simplicity's sake.

Solute name Formula Name in pytzer
Tris (HOCH2)3CNH2 tris

Literature references

References from the peer-reviewed literature (or 'sources') are written as the initials of the surname of up to the first four authors, followed by the final two digits of the publication year. Extra bits may be added to distinguish between publications that would end up with the same code. In alphabetical order of the source's code:

Source Full citation
A92ii Archer, D. G. (1992). Thermodynamic Properties of the NaCl + H2O System. II. Thermodynamic Properties of NaCl(aq), NaCl·2H2(cr), and Phase Equilibria. J. Phys. Chem. Ref. Data 21, 793–829. doi:10.1063/1.555915.
A99 Archer, D. G. (1999). Thermodynamic Properties of the KCl+H2O System. J. Phys. Chem. Ref. Data 28, 1–17. doi:10.1063/1.556034.
AW90 Archer, D. G., and Wang, P. (1990). The Dielectric Constant of Water and Debye‐Hückel Limiting Law Slopes. J. Phys. Chem. Ref. Data 19, 371–411. doi:10.1063/1.555853.
CMR93 Campbell, D. M., Millero, F. J., Roy, R., Roy, L., Lawson, M., Vogel, K. M., et al. (1993). The standard potential for the hydrogen-silver, silver chloride electrode in synthetic seawater. Mar. Chem. 44, 221–233. doi:10.1016/0304-4203(93)90204-2.
CRP94 Clegg, S. L., Rard, J. A., and Pitzer, K. S. (1994). Thermodynamic properties of 0–6 mol kg–1 aqueous sulfuric acid from 273.15 to 328.15 K. J. Chem. Soc., Faraday Trans. 90, 1875–1894. doi:10.1039/FT9949001875.
dLP83 de Lima, M. C. P., and Pitzer, K. S. (1983). Thermodynamics of saturated electrolyte mixtures of NaCl with Na2SO4 and with MgCl2. J. Solution Chem. 12, 187–199. doi:10.1007/BF00648056.
GM89 Greenberg, J. P., and Møller, N. (1989). The prediction of mineral solubilities in natural waters: A chemical equilibrium model for the Na-K-Ca-Cl-SO4-H2O system to high concentration from 0 to 250°C. Geochim. Cosmochim. Acta 53, 2503–2518. doi:10.1016/0016-7037(89)90124-5.
GT17 Gallego-Urrea, J. A., and Turner, D. R. (2017). Determination of pH in estuarine and brackish waters: Pitzer parameters for Tris buffers and dissociation constants for m-cresol purple at 298.15K. Mar. Chem. 195, 84–89. doi:10.1016/j.marchem.2017.07.004.
HM83 Holmes, H. F., and Mesmer, R. E. (1983). Thermodynamic properties of aqueous solutions of the alkali metal chlorides to 250 °C. J. Phys. Chem. 87, 1242–1255. doi:10.1021/j100230a030.
HMW84 Harvie, C. E., Møller, N., and Weare, J. H. (1984). The prediction of mineral solubilities in natural waters: The Na-K-Mg-Ca-H-Cl-SO4-OH-HCO3-CO3-CO2-H2O system to high ionic strengths at 25°C. Geochim. Cosmochim. Acta 48, 723–751. doi:10.1016/0016-7037(84)90098-X.
HM86 Holmes, H. F., and Mesmer, R. E. (1986). Thermodynamics of aqueous solutions of the alkali metal sulfates. J. Solution Chem. 15, 495–517. doi:10.1007/BF00644892.
HPM88 Hershey, J. P., Plese, T., and Millero, F. J. (1988). The pK1* for the dissociation of H2S in various ionic media. Geochim. Cosmochim. Acta 52, 2047–2051. doi:10.1016/0016-7037(88)90183-4.
HPR93 Hovey, J. K., Pitzer, K. S., and Rard, J. A. (1993). Thermodynamics of Na2SO4(aq) at temperatures T from 273 K to 373 K and of {(1-y)H2SO4+yNa2SO4}(aq) at T = 298.15 K. doi:10.1006/jcht.1993.1016.
M88 Møller, N. (1988). The prediction of mineral solubilities in natural waters: A chemical equilibrium model for the Na-Ca-Cl-SO4-H2O system, to high temperature and concentration. Geochim. Cosmochim. Acta 52, 821–837. doi:10.1016/0016-7037(88)90354-7.
MP98 Millero, F. J., and Pierrot, D. (1998). A Chemical Equilibrium Model for Natural Waters. Aquat. Geochem. 4, 153–199. doi:10.1023/A:1009656023546.
P91 Pitzer, K. S. (1991). “Ion Interaction Approach: Theory and Data Correlation,” in *Activity Coefficients in Electrolyte Solutions, 2nd Edition*, ed. K. S. Pitzer (CRC Press, Florida, USA), 75–153.
PP82 Peiper, J. C., and Pitzer, K. S. (1982). Thermodynamics of aqueous carbonate solutions including mixtures of sodium carbonate, bicarbonate, and chloride. J. Chem. Thermodyn. 14, 613–638. doi:10.1016/0021-9614(82)90078-7.
PP87i Pabalan, R. T., and Pitzer, K. S. (1987). Thermodynamics of NaOH(aq) in hydrothermal solutions. Geochim. Cosmochim. Acta 51, 829–837. doi:10.1016/0016-7037(87)90096-2.
PP86ii Phutela, R. C., and Pitzer, K. S. (1986). Heat capacity and other thermodynamic properties of aqueous magnesium sulfate to 473 K. J. Phys. Chem. 90, 895–901. doi:10.1021/j100277a037.
RC99 Rard, J. A., and Clegg, S. L. (1999). Isopiestic determination of the osmotic and activity coefficients of {zH2SO4+ (1−z)MgSO4}(aq) at T = 298.15 K. II. Results for z = (0.43040, 0.28758, and 0.14399) and analysis with Pitzer's model. J. Chem. Thermodyn. 31, 399–429. doi:10.1006/jcht.1998.0461.
RGB80 Roy, R. N., Gibbons, J. J., Bliss, D. P., Casebolt, R. G., and Baker, B. K. (1980). Activity coefficients for ternary systems: VI. The system HCl + MgCl2 + H2O at different temperatures; application of Pitzer's equations. J. Solution Chem. 9, 911–930. doi:10.1039/F19827801405.
RGO82 Roy, R. N., Gibbons, J. J., Ovens, L. K., Bliss, G. A., and Hartley, J. J. (1982). Activity coefficients for the system HCl + CaCl2 + H2O at various temperatures. Applications of Pitzer's equations. J. Chem. Soc., Faraday Trans. 1 78, 1405–1422. doi:10.1039/F19827801405.
RM81i Rard, J. A., and Miller, D. G. (1981). Isopiestic Determination of the Osmotic Coefficients of Aqueous Na2SO4, MgSO4, and Na2SO4-MgSO4 at 25 °C. J. Chem. Eng. Data 26, 33–38. doi:10.1021/je00023a013.
SRM87 Simonson, J. M., Roy, R. N., Mrad, D., Lord, P., Roy, L. N., and Johnson, D. A. (1987). The thermodynamics of aqueous borate solutions II. Mixtures of boric acid with calcium or magnesium borate and chloride. J. Solution Chem. 17, 435–446. doi:10.1007/BF00647311.
SRRJ87 Simonson, J. M., Roy, R. N., Roy, L. N., and Johnson, D. A. (1987). The thermodynamics of aqueous borate solutions I. Mixtures of boric acid with sodium or potassium borate and chloride. J. Solution Chem. 16, 791–803. doi:10.1007/BF00650749.
WM13 Waters, J. F., and Millero, F. J. (2013). The free proton concentration scale for seawater pH. Mar. Chem. 149, 8–22. doi:10.1016/j.marchem.2012.11.003.
ZD17 Zezin, D., and Driesner, T. (2017). Thermodynamic properties of aqueous KCl solution at temperatures to 600 K, pressures to 150 MPa, and concentrations to saturation. Fluid Phase Equilib. 453, 24–39. doi:10.1016/j.fluid.2017.09.001.

What actually matters?

For solutes, you could actually use whatever name you like, as long as it was applied consistently throughout the first four items on the list at the top of this page (i.e. in input files, in the ions variable, in the cfdict, and in the pytzer.props functions). If it was your heart's desire, you could rename Na (sodium ion) as GentooPenguin in all of these places, and everything should still work fine. Using a matching name in the corresponding interaction coefficient functions is also required, in order to use the CoefficientDictionary methods like get_contents.

The codes used for different references are for convenience only; they do not affect the program. However, they do define the output from CoefficientDictionary.print_coeffs.