Modeling Tools


  • A software package used to calculate thermodynamic properties for minerals, gases, aqueous species, and reactions at high temperatures and pressures.
  • For this version of sᴜᴘᴄʀᴛ (sᴜᴘᴄʀᴛʙʟ), we used a more recent mineral database of Holland and Powell (2011) and modified the computer code accordingly to accommodate the different heat capacity function, volume as a function of temperature and pressure, and mineral phase transition using the Landau model (Holland and Powell, 1998).
  • We also added more species to the database. For example, we included arsenic minerals and aqueous species, aluminum species from Tagirov and Schott (2001), aqueous silica from Rimstidt (1997), and dawsonite from Benezeth et al. (2007). Please refer to Zimmer et al. (2016). The stated temperature and pressure ranges for aqueous species are from 1 to 5000 bars and 0° to 1000°C, but for minerals the ranges exceed the original limits stated in Johnson et al. (1992), but vary for individual species.


  • ᴘʜʀᴇᴇǫᴄ is a geochemical modeling software distributed by the U.S. Geological Survey and developed by David Parkhurst and Tony Appelo. It is written in the C and C++ programming languages and is designed to perform a wide variety of aqueous geochemical modeling calculations.
  • Here, the online version ᴘʜʀᴇᴇǫᴄ has new databases phreeqc-bl.dat and llnl-bl-kinetics.dat, which have thermodynamic properties consistent with those in Zimmer et al. (2016) and allow ᴘʜʀᴇᴇǫᴄ calculations at elevated temperature and pressure. llnl-bl-kinetics.dat also has a library of BASIC language RATES blocks for about 100 minerals and log K for related PHASES.


  • An interactive program, developed to link sᴜᴘᴄʀᴛʙʟ and ᴘʜʀᴇᴇǫᴄ to facilitate modeling at temperatures and pressures suitable for clastic and carbonate diagenesis, geological carbon storage, and geothermal applications.
  • Supᴘʜʀᴇᴇǫᴄ converts the log K values of aqueous, mineral and gas species reactions from the output of sᴜᴘᴄʀᴛʙʟ at user specified temperatures and pressures and the associated molar volume parameters for each species into the format of the ᴘʜʀᴇᴇǫᴄ database.
  • Two databases diagenesis.dat (0.01 – 100 oC at 1 bar and 100-200 oC at Psat) and with pressure correction up to 1 kb) and geothermal.dat (0.01 - 100 oC at 1 bar and 100-300 oC at Psat) are provided with the online ᴘʜʀᴇᴇǫᴄ program.
  • Users can generate a database bl-dat at temperature up to 1000 oC and pressure up to 5000 bars but currently the ᴘʜʀᴇᴇǫᴄ code is limited to 330 oC. We are working on it.