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Paul Scherrer Institut PSI GEM Software (GEMS) Home

Paul Scherrer Institut
5232 Villigen PSI, Schweiz/Switzerland
Tel. +41 56 310 21 11
Fax. +41 56 310 21 99

E-Mail: gems2.support@psi.ch

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GEMS TDB Technical Information 

GEM-Selektor version 3.2 and higher:

The installed GEM-Selektor program looks for the default thermodynamic database files in the following directory:


The exact form of <gems3-app> depends on the PC platform, e.g.

Mac OS "/Applications/Gems3.app/Contents/"
Linux "~/Gems3-app/"
Windows "C:\Selektor\Gems3-app\"

Each file in GEMS database format, e.g. phase.supcrt.inorg.ver1998.pdb, comes with an (automatically created) index part, e.g. phase.supcrt.inorg.ver1998.ndx. This index file is used by the program to speed-up reading of database files and linking them into the database chains. For brevity, the *.ndx files are not shown in the lists below.

Important:  If you used the GEM-Selektor before the release of version 3.2 (30.04.2013) then we recommend installing GEM-Selektor version 3.2 in a different folder in order to avoid mixing of files belonging to the "new" TDB and "old" TDB in the "/DB.default" folder. Alternatively, first rename the "gems3-app" folder in the location where GEMS3 was installed into "gems3-app-old"; then re-install GEM-Selektor to the usual location. For Mac users: simply remove the "gems3.app" from "/Applications" and put there the new "gems3.app" from the version 3.2 dmg installer.

1. PSI/Nagra part of GEMS default database is located in files:

In the GEMS version of the PSI/Nagra TDB 12/07, the core data and the recommended application data are taken together (they are referred to as recommended data) and are separated from the supplemental data in such a way that new modeling projects can be made with recommended data only, or with a combination of recommended and supplemental data. There is no use in calculations with the supplemental data only. The following database files concerning the PSI/Nagra TDB 12/07 are contained in the /DB.default folder:

sdref.psi-nagra.rec.refs.ver12-07.v0.1.pdb bibliographic references (SDref records)
icomp.psi-nagra.rec.elements.ver12-07.v0.1.pdb elements (IComp records)
dcomp.psi-nagra.rec.solids.ver12-07.v0.1.pdb recommended solids (DComp records)
reacdc.psi-nagra.rec.solids.ver12-07.v0.1.pdb recommended solids (ReacDC records)
dcomp.psi-nagra.rec.gases.ver12-07.v0.1.pdb recommended gases (DComp records)
reacdc.psi-nagra.rec.gases.ver12-07.v0.1.pdb recommended gases (ReacDC records)
dcomp.psi-nagra.rec.aqueous.ver12-07.v0.1.pdb recommended aqueous species (DComp records)
reacdc.psi-nagra.rec.aqueous.ver12-07.v0.1.pdb recommended aqueous species (ReacDC records)
phase.psi-nagra.rec.phases.ver12-07.v0.1.pdb recommended phases (Phase records)

compos.psi-nagra.pco.generic.ver12-07.pdb predefined composition objects (Compos records)

reacdc.psi-nagra.sup.solids.ver12-07.v0.1.pdb supplemental solids (ReacDC records)
reacdc.psi-nagra.sup.aqueous.ver12-07.v0.1.pdb supplemental aqueous species (ReacDCC records)
phase.psi-nagra.sup.phases.ver12-07.v0.1.pdb supplemental phases (Phase records)

As discussed here, the PSI/Nagra TDB 12/07 can also be used together with the SUPCRT92 part of the default database.

2. SUPCRT92 part of the default database (imported) is located in files:

icomp.supcrt.ver1998.pdb elements (IComp records)
sdref.supcrt.refs.ver1998.pdb bibliographic references (SDref records)
dcomp.supcrt.organic.ver1998.pdb organic aqueous species and gases (DComp records)
phase.supcrt.inorg.ver1998.pdb phases (Phase records)
inorganic solids (DComp records)
dcomp.supcrt.inorg.gases.ver1998.pdb inorganic gases (DComp records)
dcomp.supcrt.inorg.aqueous.ver1998.pdb inorganic aqueous species (DComp records)
compos.supcrt.pco.inorg.ver1998.pdb predefined composition objects (Compos records)

The SUPCRT92 part of the default database can be used either alone or combined with the PSI/Nagra TDB 12/07.

3. Supporting database files

sdref.support.template.scripts.ver3.0.pdb collection of templates for print/export, import and math scripts (SDref records)

This default script library consits of a collection of SDref records that contain print/export, import, and template math scripts that should help users to perform data import/export operations and to write math scripts. This default script library is located in the sdref.template.scripts.*  files in the /program/DB.default directory. The files can be manually linked to any user-created modelling project to make the script libraries accessible  within the project database.

GEM-Selektor version 3.1 and lower:

These installers contain the Nagra-PSI 01/01 dataset as default (kernel) TDB, now superceded with the PSI/Nagra 12/07 dataset (see above). These files are listed below for compatibility with earlier releases of GEMS. 

Each GEMS database file, e.g. rtparm.nagra-psi.pdb, comes with an (automatically created) index counterpart, e.g. rtparm.nagra-psi.ndx. This index file is used by the program to speed-up reading of database files and linking them into database chains. For brevity, the *.ndx files are not shown in the lists below.

"Kernel" part of the GEMS default database is located in files:






phase.kernel.nagra-psi.solutions.pdb  (under construction)

The following files are not used when records are copied into a new project directory:

reacdc.nagra_psi.pronsprep.pdb   (Auxiliary reactions for PRONSPREP estimates)
rtparm.nagra-psi.pdb                           (Examples of T,P corrections - under construction)

"Complementary" part of the default database (imported SUPCRT data) is located in files:






sdref.complem.pdb  (Bibliographic references to complementary data base)

Last updated:  30. 04. 2013

Copyright (c) 2003-2013  GEMS Development Team.