GEMS Development Team
GEM Software is developed since 1996 (since 2000 at PSI). Since March 2008,
GEMS is developed jointly by the PSI team (D. Kulik, S. Dmytrieva,G.
Hingerl) and by the ETHZ IGP team (T. Wagner, G. Dan Miron); T.Wagner (now at University of Helsinki, Finland) actively used and
improved GEMS since mid-2004.
Dmitrii A. Kulik,
team leader (Paul Scherrer Institut):
theoretical and practical development of GEM IPM
algorithm, its accuracy and phase
stability criteria; general design
of GEM-Selektor and GEMS3K codes, documentation, help, web
pages; co-development of TSolMod
class library of built-in models of mixing in phases-solutions; co-development of the GEMSFIT code (since January 2013).
Svitlana V. Dmytrieva
(now at Ciklum Interactive Solutions, Kyiv, Ukraine)
wrote the database management, script interpreter, process simulator,
sampler and many other modules of Selektor-A code in 1991-1996. She
re-wrote Selektor-A code from C into the GEM-Selektor code in C++ in
1996-2002. At present, she maintains and develops the GEM-Selektor GUI based on the Qt UI framework. She is also
involved in optimization and improvement of
GEMS3K and GEMSFIT codes.
Zurich; since 1.08.2012 Division
of Geology, University of Helsinki, Finland), prominent
expert in geochemistry of ore deposits and geochemical thermodynamics.
His main interest lies in thermodynamically consistent implementation
of complex non-ideal solution models for rock-forming minerals, fluids,
and ore minerals, as well as in methods of T-P correction of
thermodynamic data and in advanced applications of thermodynamic
modeling in hydrothermal ore geochemistry. T.Wagner
is a co-developer of GEM algorithms and GEM-Selektor
code, and a leading developer of
the TSolMod class library of built-in
models of mixing in phases-solutions.
(Paul Scherrer Institut), leading expert in hydrogeochemical mass
transport modelling. He participates in development of GEMS3K code,
especially its interface for data exchange within coupled reactive
transport codes, in particular OpenGeoSys-GEMS. His contribution was
crucial in dramatic improvement of stability and precision of
G. Dan Miron (IGP ETH Zurich), since September 2012 main developer of GEMSFITS codes in framework of his PhD project. In particular, the code
functionality is extended to fitting not only interaction parameters of
mixing in non-ideal phases, but also thermodynamic properties of
phase components, as well as inverse titrations, thermobarometry
and other applications.
Allan M.M. Leal (Paul
Scherrer Institut), the author of novel, robust and efficient
equilibrium methods and reactive transport solvers implemented in the Reaktoro unified framework
for modeling reactive chemical systems. He participates in developing
the next-generation numerical kernel GEMS4K for GEM Software, achieved
by combining both GEMS3K and Reaktoro codes.
(Paul Scherrer Institut) is an expert in geochemical modeling and
thermodynamic databases, in particular, one of authors of Nagra-PSI 01/01 database.
He maintains the default 'Kernel'
Nagra-PSI default chemical
thermodynamic data base distributed with the GEM-Selektor
Urs Berner (Paul
Scherrer Institut) is a leading expert in thermodynamic modeling of
radionuclide solubility limits in cement, clay and other aquatic
systems of relevance for radioactive waste management. He is the
main peer in testing new functionality of GEMS and defining roadmaps of
its future development.
Enzmann (Geowissenschaften, JOGU Mainz, Germany): Improvement of
module of GEM-Selektor for 1-D coupled
reactive transport simulations.
(Paul Scherrer Institute): Supplied the source C++ code of
Churakov-Gottschalk EoS for gas/fluid mixtures, adapted as part of the TSolMod library.
Switzerland): leading expert in thermodynamic modeling of cement
hydration and degradation. Preparation of the Cemdata'07 - a
thermodynamic database for cement
systems in GEM-Selektor format. This database is available as a GEMS3
database plugin at http://www.empa.ch/cemdata
Sergii Nichenko (Paul Scherrer Institut): works
on thermodynamic modeling of nuclear materials, in particular complex
mixed systems such as nuclear fuels and molten salts, as well as
evaluation of thermophysical and thermodynamic properties by MD/MC
(molecular dynamics - Monte Carlo) methods.
(Forschungszentrum Julich): expert in thermodynamic modeling of solid-gas
systems related to nuclear materials. She develops and maintains the HERACLES
thermodynamic database in GEM-Selektor format. This database for
nuclear engineering applications is available as GEMS3 default database
Implementation of GEM-Selektor and GEMS3K codes
would not have been possible without people who contributed much to
development of the preceding Selektor-A code and thermodynamic
V. Chudnenko (Institute
Irkutsk, Russia) created earlier SELEKTOR
codes for IBM/360 compatible mainframes and maintains the alternative
Selektor-W code that use the same GEM IPM algorithms but have different
format of thermodynamic database and text-based
user's interface. He contributed a lot in incorporating the proprietary
IPM modules into Selektor-A codes in 1990-1996, and upgrading it into a
high-precision IPM-2 module of GEM-Selektor in 2000-2001.
Igor K. Karpov (Institute of Geochemistry, Irkutsk, Russia),
creator of the
convex programming GEM approach (theoretical development, algorithms,
applications, scientific mentorship). In early
1970s he initiated the development of SELEKTOR codes and promoted this
technique over 30 years, leading the Laboratory for
Physicochemical Modeling. Prof. Karpov passed away in March 2005;
the Laboratory is now headed by Prof. K.Chudnenko.
Andriy V. Rysin designed
window/page screen forms and many other GUI elements in Linux version
of the GEM-Selektor code. In 2001-2002, he connected these
windows and dialogs to the Qt UI
Toolkit, ported GEMS to various platforms, designed an improved
GraphDialog and other user-interface utilities.
Vasilii A. Sinitsyn
(Kyiv State University, Ukraine) in 1990-1996 took part in in
inplementation of modules for
calculation of thermodynamic data and development of DComp and
ReacDC formats in Selektor-A code. He also contributed
to compilation of thermodynamic database and performed many modeling
Gottschalk (GFZ Potsdam, Germany): Conversion of a chemical
thermodynamic database for metamorphic minerals and fluids into
GEM-Selektor format (in 2004-2005).
Hingerl (ETH Zurich and PSI, since August 2012 at ERE, Stanford
University, USA) from 2008 to 2012 contributed in extending TSolMod and GEMS3K
codes with Pitzer, Extended UNIQUAC, and rEUNIQUAC models for
electrolytes over wide
ranges of temperature and pressure (in association with the CCES GEOTHERM
project). SInce 2010 until mid-2012 he has been develooping the GEMSFIT
parameter fitting code for aqueous activity models.
(Kyiv) has translated SUPCRT92 subroutines from fortran to C and
built them into Selektor-A package in 1991-1993.
Yuri A. Shybetsky
(Kyiv) in 1996-1997 has extended Selektor-A and its thermodynamic
database to isotopic systems and worked on
analysis and propagation of the uncertainty of thermodynamic data.
Irina L. Kolyabina
(Institute of Environmental Geochemistry, Kyiv) in 1996-1999 worked on
extension of the Selektor-A built-in thermodynamic database.
(now in Houston, USA) helped us in 1997-1999 at SSE Technocentre,
to test and set up surface complexation models in GEM implementation
and to compare them with LMA (FITEQL3) results.
DK wishes to thank
Prof. V.B.Koval, Prof. E.V.
Sobotovich, Prof. V.V.Tokarevsky; Dr. M.S.Khodorivsky and
Dr. V.A.Sinitsyn for the administrative help and support during his
terms in Kyiv
institutions (SSE Technocentre, Institute of Environmental
Geochemistry). He thanks many colleagues and students for discussions
criticism related to earlier versions of GEM-Selektor codes.
Further, DK thanks
Prof. Jan Harff
(Institute for Baltic Sea Research, Warnemuende, Germany) for
constructive support during his work there in 1992-1993 and
1998; to Prof. S.U.Aja (Brooklyn College of CUNY) for his support
while hosting DK and VS during their NAS/NRC OCEE
exchange visits in 1996-1997. Special thanks are to Prof.
Michael Kersten (Johannes-Gutenberg University, Mainz) for quite
productive collaboration since 1997 on many SSAS modeling topics,
promotion of GEMS development, and purchase of the first Qt
DK and SD also acknowledge the
friendly and constructive help from Drs. U.Berner, E.Curti, W.Hummel,
T.Thoenen, and other people at LES PSI during research visits in Spring
resulted in the development of PM2SEL utility program, and their
continuous support of GEMS development since June 2000. Finally, we are
grateful to Dr. V.A.Pokrovskii for sending us the
SUPCRT92 program and to Prof. D.A.Sverjensky (Johns Hopkins
University, Baltimor, USA) for providing the PRONSPREP97 code.
Parts of work
on GEMS development have
been indirectly supported since 1990 through a number of research
grants from the Ukrainian Foundation for Basic Research, Ministry
of Chornobyl (Ukraine), International Science Foundation, Deutsche
Forschungsgemeinschaft, European Science Foundation, NAS/NRC OCEE
Radioactive Waste Program, and other public non-commercial sources.
Since June 2000, development of GEMS code has been
taken over by the Waste Management Laboratory of the Paul Scherrer
Institute; constructive help of the Laboratory Heads, Dr. J.Hadermann
and Dr. M.Bradbury,
and partial financial support from Nagra are gratefully appreciated.
Last but not least, the Team is grateful to Dr. Gillian Gruen
ETH Zurich) for professional design of an exciting set of icons used in
GEM-Selektor Graphical User Interface and on GEMS help and web pages.
GEMS Development Team acknowledges recent and on-going support that
comes from various sources, among others:
(Swiss National Cooperative for the Disposal of Radioactive Waste),
project of the Competence Center Environment and Sustainability of
the ETH Domain (CCES) (2008-2012);
project of the European Atomic Energy Community's Seventh
Framework Programme FP7 (2011-2013);
Fluid chemistry and fluid-rock
interaction of Alpine veins, Central Alps (T.Wagner, SNF funded);
Internally-consistent thermodynamic data
for fluid-rock equilibria: Development and applications (T.Wagner,
Sinergia project "Stable phase
composition in novel cementitious systems: C(-A)-S-H" (SNF-funded);
Sinergia project "COTHERM - COmbined
hydrological, geochemical and geophysical modelling of geotTHERMal
GEM-Selektor belongs to a
SELEKTOR family of program codes that implement a convex programming
approach to Gibbs energy minimization calculations of chemical
equilibria, developed since 1974 in
the laboratory of Prof. Igor
K.Karpov at the A.P.Vinogradov Institute of Geochemistry,
The first Selektor
(based on a combination of "steepest descent" and Newton
minimization algorithms) for BESM-6 mainframes appeared in 1975.
Since then, the code was used in many academic institutions
in the former USSR to solve chemical equilibrium problems
in various scientific and applied fields. The modern IPM
minimization algorithm has been developed by I.K.Karpov,
V.A.Detkovskaya and K.V.Chudnenko in 1984-1988. At the same time, a
Selektor-3 code has been re-written in PL/1 for IBM-360 compatible
Selektor implementation on PC was suggested by D.Kulik in 1990,
when a collaboration between his group at the academic Institute of
Geochemistry and Mineral Physics, Kyiv (Ukraine) and Prof. Karpov's
laboratory (Irkutsk, Russia) was established. Since then (in
1991-1999), D.Kulik's group at the Environmental Radiogeochemistry
Centre and the SSE
Technocentre, Kyiv, Ukraine (S.Dmitrieva), collaborated in the
development and application of SELEKTOR codes.
activities became even more international since 1992,
supported in part through several research grants (International
Science Foundation, Deutsche Forschungsgemeinschaft, European Science
Foundation, NAS/NRC OCEE Radioactive Waste Program) and scientific
excahnge programs for D.A.Kulik (at Institute for Baltic
Sea Research Warnemuende,Rostock; University of Bonn; J.Gutenberg
University, Mainz, Germany; Brooklyn College of CUNY, USA; Paul
Scherrer Institute, Switzerland). Most of this support was aimed
at development of geochemical modeling applications in marine- and
environmental geochemistry; naturally, this work gave important
feedback and ideas for improvement and further development of software
and thermodynamic database. This work has also resulted in an
extension of GEM technique to surface complexation on
mineral-water interfaces (Kulik, 2000, 2002, 2006), which has been
implemented since 1995 in Selektor-A and GEMS version 1 codes.
Since June 2000,
development of GEMS code has been taken over by the Waste
Management Laboratory at the Paul Scherrer Institute (Switzerland)
in continuing collaboration with Prof. Karpov's laboratory and SSE
Technocentre, Kiev (S.Dmitrieva). in 2001, the GEM IPM module
(numerical "engine" of Selektor codes) has been upgraded into an
IPM-2 module, yielding a 9 order of magnitude gain in
the mass-balance precision of GEM technique, which made it possible to
use GEM in most demanding
geochemical applications involving trace elements and radionuclides.
The IPM-2 module, together with an improved graphical user's interface
powered by the Qt Toolkit, forms a basis of GEM-Selektor v.2-PSI
The first release
GEMS-PSI version 2.0 code with built-in edition of NAGRA-PSI
thermochemical database, oriented mainly to aquatic systems and
applications in performance assessment in radioactive waste disposal,
took place by the end of 2003 on this web site (http://gems.web.psi.ch/).
Since 2008, the
GEM-Selektor code is developed jointly by the PSI LES
the ETHZ IGP teams. The emphasis of PSI team is in modeling
applications of GEMS and GEMS3K (formerly GEMIPM2K) for scientific
issues related to
nuclear waste disposal. The emphasis of IGP team is in modeling
applications of both codes in various areas of hydrothermal ore
geochemistry and geothermal research. Conversely, this collaborative
development is expected to lead to much broader acceptance of
GEM-Selektor in geochemical research community. These efforts led to
even more stable and precise GEM IPM algorithm, as well as introduction
of the TSolMod class library and data interface for built-in models of
mixing of phases-solutions. The present GEM-Selektor v.3 and GEMS3K
codes comprise the outcome of these efforts.
Since 2013, after Prof. T.Wagner move to University of Helsinki
(UH), Finland, GEM Software is developed jointly by PSI LES, UH
and ETHZ IGP teams.
(c) 2003-2013 GEMS Development Team