GEM Software: 

Examples and Test Projects

The GEM-Selektor v3 test suite is a set of small modelling projects with short descriptions of model system setup and expected results. Some tests are included into GEMS3 installer (see "Gems3-app/Resources/projects/"); they will be automatically copied in the user projects directory (e.g. "/Library/Gems3/projects/") upon the first installation; upon the upgrade, only the former location will be updated by the GEMS installer.

Descriptions of test projects imply that the user has already worked through the runtime Tutorial and is familiar with the program on a basic technical level.


Test modeling project
Calculations of aqueous molal activities and activity coefficients
To check calculations of aqueous speciation and mineral solubility-pH diagrams
Kinetics To test metastability constraints and simulations of simple mineral dissolution and precipitation kinetics
To check calculation and plotting of simple P-T mineral stability diagrams
To check calculations of temperature- pressure dependent mineral equilibria without aqueous electrolyte
To check the export of GEMS3K I/O files for standalone codes
Ca-Sr-CO3 To check calculations of aqueous- solid solution equilibria and Lippmann diagrams
To test calculations of equilibria involving PRSV (Peng-Robinson-Stryjek-Vera) non-ideal gas/fluid model
To test calculations of equilibria involving SRK (Soave-RedlichKwong) non-ideal gas/fluid model
To test calculations of equilibria involving CoRK (Compensated Redlich-Kwong) non-ideal gas/fluid model
To test calculations of equilibria involving CG EoS (Churakov-Gottschalk) non-ideal gas/fluid model
To check how miscibility gaps in solid solution systems can be computed and plotted
To check thermodynamic data included in the old kernel Nagra-PSI database (GEMS v. 3.1 and lower)
TestPNTDB To check thermodynamic data included in the updated PSI/Nagra database (GEMS v. 3.2 and higher)
To check calculations of titration and pH-step diagrams for surface complexation models

(always under construction)

How to work with test projects

Some test projects (as folders) are included into the GEM-Selektor installer under "Gems3-app/Resources/projects/". Each project is also available separately for downloading as a zip archive file (see link in the respective web page) which contains the whole project directory. After downloading, simply unpack the directory to a temporary location on your hard disk and copy it as a whole into the "Library/GEMS3/projects/" subdirectory of your GEMS3 installation directory.

If, by re-calculating systems or processes in this test project, you obtain results or curves that significantly differ from those given in the description page, please do not hesitate to send as a bug report per email.

Last updated:  30.04.2013 DK

Copyright (c) 2012-2013  GEMS Development Team