Thermodynamics in Internet


The appearance and wide spreading of the world wide nets mark the new stage in development of thermodynamic modeling. Now one can use the remote computers for the calculations. However the standalone computers still keep their positions and it is more comfortable to have own software on the table.

Below are listed the references to some interesting sites where thermodynamic and thermochemical information can be found. The list inevitably is not full and contains only those references that I have managed to find. The brief descriptions are borrowed from the original sources.


This site provides thermochemical, thermophysical, and ion energetics data compiled by NIST under the Standard Reference Data Program. NIST has a long history as the source for reliable thermochemical data starting from the 1920's with the International Critical Tables. The tradition continues as new SRD databases on thermochemical properties of inorganic and small organic molecules gain acceptance.

The NIST Chemistry WebBook (free online system) contains:

·        Thermochemical data for over 6000 organic and small inorganic compounds:

o   Enthalpy of formation

o   Enthalpy of combustion

o   Heat capacity

o   Entropy

o   Phase transition enthalpies and temperatures

o   Vapor pressure

·        Reaction thermochemistry data for over 9000 reactions.

o   Enthalpy of reaction

o   Free energy of reaction

This site provides data from famous reference book NIST-JANAF Thermochemical Tables.

The Thermodynamics Research Center (TRC) specializes in the collection, evaluation and correlation of thermophysical, thermochemical and transport property data for organic compounds.  As a part of the Physical and Chemical Properties Division at National Institute of Standards and Technology, TRC is located in Boulder, Colorado.

    A goal of TRC is to establish a large, general-purpose archive of experimental data covering thermodynamic, thermochemical, and transport properties for pure compounds and mixtures of well-defined composition, and to maintain coverage as new data appear.  It is critically important that the data evaluation includes the estimated uncertainties for practically all the numerical data stored.  This feature allows, in principle, determination of the quality of recommended data based upon the original experimental data collected at TRC. 

    There are four major types of information stored in this archive - an in-house database.

·        Compound Identification. Registry numbers identify pure compounds and components of mixtures throughout the archive. Registry numbers link to an empirical formula, a coded representation of the structural formula, and to one or more names. The database contains 113,000 registry numbers and 218,000 names. Reacting systems of one or more compounds also receive registry numbers. Among the stored compounds, approximately 15,800 pure compounds, 9,000 binary and ternary mixtures, and some 2,500 reaction systems have data records. Chemical reactions have a classification code and registry numbers of four species in the reaction.

·        Sample Descriptions. The database describes over 17,900 distinct samples used in property measurements. The description includes: source of sample, method of purification, and final purity as reported by the authors of the document. Formal abbreviations exist, and by sample numbers identify different samples of the same compound used for measurements in the same document.

·        Literature References. The database contains citations of original documents and associated information (such as titles, document types, classification of information, and comments) and links to data values. Names of authors appear in a dedicated table linked to the citations. Thus, it is possible to retrieve literature references by year of publication, author, compound identity, property, or combinations of them. The database contains 82,000 citations, of which, over 22,000 citations contribute numerical values to the database.

·        Numerical Values. Each numerical property value appears in a data record.  A data record also contains values of state variables, and an estimate of the uncertainty of the property. Each data record links to the three kinds of information listed above to codes that identify the property, the primary phase, other phases in equilibrium with the primary phase, other information about the way the data appear in the original document, and a trail of its entry into the database. Property values are converted to SI units on entry while retaining sufficient information to regenerate the original numbers. The database now contains 850,000 data records.


SGTE is a consortium of centers engaged in the development of thermodynamic databanks for inorganic and metallurgical systems and their application to practical problems. The aims of organization are

·        The provision, maintenance and expansion of high quality databases, that enable the user to undertake complex calculations of chemical equilibrium efficiently and reliably.

·        Cooperation in a broader international effort to unify thermodynamic data and assessment methods; also to promote collaborative efforts.

SGTE centers (references are borrowed from the original site, but many of them were not valid when this page was updated 12.11.2013)

·        France

·        Germany

·        Sweden


CompuTherm LLC provides powerful and easy to use phase diagram and thermodynamic calculation software tools for industrial, academic, and educational use. Professor Y. Austin Chang, Wisconsin Distinguished Professor and member of the National Academy of Engineering, started calculating phase diagrams at the University of Wisconsin-Madison in the 1980's. In 1996, CompuTherm LLC was established to focus on the development of phase diagram calculation software.

Pandat is a software package for calculating phase diagrams and thermodynamic properties of multi-component alloys (S.-L. Chen, et al, The PANDAT software package and its applications // CALPHAD. – 2002. - V.26, 2. – P. 175-188; W. Cao, et al. PANDAT software with PanEngine, PanOptimizer and PanPrecipitation for multi-component phase diagram calculation and materials property simulation // CALPHAD. - 2009.-V. 33. - P.328-342).

 GEM-Selektor (GEMS) is a research program package for interactive thermodynamic modelling of aquatic (geo)chemical systems. GEMS includes a default (kernel) thermodynamic database imported from Nagra/PSI chemical thermodynamic data base 01/01. The systems may involve metastable minerals, solid solution - aqueous solution equilbria, gas mixtures, and multi-site-surface sorption on mineral-water interfaces. Processes of irreversible chemical mass transfer can be simulated from the principles of local and partial equilibrium.

GEMS belongs to a family of SELEKTOR program codes that implement Karpov's convex programming approach to Gibbs energy minimization calculations of heterogeneous multi- phase-component chemical equilibria. SELEKTOR codes were developed since 1975 in an academic environment on a non-commercial basis in Russia, Ukraine, Germany, USA and Switzerland. Since June 2000, development of GEM-Selektor was taken over by the LES Thermodynamics and Geochemical Modelling Group, where it continues, retaining its open international character (GEMS Development and Support Team).

The Department of Theoretical Process Metallurgy and Metallurgy of Nuclear Fuels at the RWTH Aachen and GTT-Technologies collaborate to offer a wide range of thermochemical services that support a growing interest in the application of thermochemistry to solving problems arising in the production and application of inorganic and organic materials. Their product ChemSage is a direct descendant of the widely used SOLGASMIX Gibbs energy minimiser program developed by Dr. Gunnar Eriksson nearly 30 years ago. ChemSage was first released in 1987 and represented a significant development of the original program. In combination, the two programs have the greatest frequency of quotation in the technical literature. The ChemSage 'engine' also forms the basis for a number of other similar software programs. ChemSage modules permit calculation of thermodynamic properties of single solution and stoichiometric condensed phases with respect to a chosen reference state, calculation of the chemical equilibrium state of a system that is defined with regard to temperature, pressure or volume, and total amounts and/or equilibrium activities of any phase constituent in the system, calculation of temperatures when precipitates are formed from the liquid, of adiabatic temperatures, simulation of a multi-stage reactor by defining energy and material flows between stages , optimisation of thermochemical data based on experimental information, results to be saved as plot-files, displayed and printed graphically, or exported to other applications. Every copy of ChemSage comes with a basic thermochemical database of approx. 1300 substances.

F*A*C*T - Facility for the Analysis of Chemical Thermodynamics - started in 1976 as a joint research project between two universities, McGill University (Professor William T. Thompson) and the École Polytechnique de Montréal (Professors Christopher W. Bale & Arthur D. Pelton), for treating thermodynamic properties and calculations in chemical metallurgy. In 1984, the research centre CRCT - Centre de Recherche en Calcul Thermochimique / Centre for Research in Computational Thermochemistry, was founded at the École Polytechnique (the engineering faculty of the Université de Montréal) in order to assist, among other things, in the promotion and development of F*A*C*T in both research and teaching. F*A*C*T has grown into a fully integrated thermochemical database that couples proven FactSage software with self-consistent critically assessed FACT thermodynamic data (Bale C.W., Chartrand P., Degterov S.A. FactSage Thermochemical Software and Databases // CALPHAD. – 2002. -V.26, 2. – P.189-228.).  Originally developed as a research tool for chemical metallurgists, F*A*C*T is now employed in many diverse fields of chemical thermodynamics by chemical engineers, corrosion engineers, organic chemists, geochemists, ceramists, electrochemists, and so on. Information about F*A*C*T databases as well as many references to similar WWW sites in inorganic chemical thermodynamics may be found at this site.

MALT2 is a comprehensive Materials-oriented Little Thermodynamic Database for Personal Computers (Yokokawa H., Yamauchi S., Matsumoto T. Thermodynamic Database MALT for Windows with gem and CJ3D // CALPHAD. – 2002. - V.26, 2. – P.155-166.). The task group of the thermodynamic database was organized in the Japan Society of Calorimetry and Thermal Analysis. MALT2stores thermodynamic data such as the standard enthalpy change for formation, DfH(298.15 K), the standard Gibbs energy change for formation, DfG(298.15K), the standard entropy, S(298.15 K), the heat capacity, Cp, and the transition temperature and the enthalpy change for transition, if any, for 4931 species; this covers those compounds important to ceramic materials, semiconductors, inorganic /organic gasses for plasma processes in semiconductors, transition metal oxides, nuclear fuels, nuclear reactor materials etc. From such stored data, the thermodynamic tables and the equilibrium constants at any temperatures can be calculated. In addition, molecular mass, coefficient of heat capacity equation, and references for data can be also available.

KINTECH company was organized by scientists and engineers from Moscow State University and the Russian Research Center "Kurchatov Institute". The flagship product is Chemical WorkBench  – the simulation software tool intended for modeling, optimization and design of a wide range of industrially, environmentally or educationally important chemistry loaded processes, reactors and technologies. Chemical WorkBench  is a chemistry-centered, desktop simulation environment for detailed, user-friendly, complete-cycle physico-chemical modeling of  the chemically-related processes, reactors and technologies (Chemical Workbench-integrated environment for materials science / M. Deminsky,  V. Chorkov,  G. Belov,  et. al. // Computational Materials Science. – 2003. -  Vol. 28, No. 2. - P.169-178.). Chemical WorkBench is a well-furnished suite of software tools enables researchers and engineers to model the "virtual prototypes" of chemically-active systems, and to simulate their operation behavior before detailed engineering and physical prototyping. Its most attractive feature is possibility to model real complicated process by means of chains of reactors. Among the reactors available there are not only equilibrium thermodynamic reactor, but also nonequilibrium reactors that take into account chemical kinetics, these are plug-flow reactor, calorimetric bomb, well-stirred reactor, etc. The researcher can combine these reactors on the virtual workbench, define links among them, set input species and parameters, accomplish calculations and visualize the results of modeling.

Kintecus - chemical modeling software for simulation of combustion, nuclear, biological, enzyme, atmospheric and many other processes. One prime feature is the ability to quickly run Chemkin/SENKIN II/III models without the use of supercomputing power or FORTRAN compiling/linking. Multiple Chemkin/freestyle thermodynamic databases can be used. Isothermal/Non-isothermal, adiabatic constant volume, constant pressure (variable volume) can easily be modeled with a flick of a switch. Programmed volume (replicating engine piston motion), programmed temperature, programmed species concentration can all easily be included in user's model WITHOUT C/FORTRAN programming. Heterogeneous chemistry is also easily modeled.

Kintecus is a compiler to model the reactions of chemical, biological, nuclear and atmospheric processes using three input spreadsheet files: a reaction spreadsheet, a species description spreadsheet and a parameter description spreadsheet. For thermodynamics, an optional thermodynamics description spreadsheet can be supplied.

The NASA Computer program CEA (Chemical Equilibrium with Applications) calculates chemical equilibrium compositions and properties of complex mixtures. Applications include assigned thermodynamic states, theoretical rocket performance, Chapman-Jouguet detonations, and shock-tube parameters for incident and reflected shocks. CEA represents the latest in a number of computer programs that have been developed at the NASA Lewis (now Glenn) Research Center during the last 45 years. These programs have changed over the years to include additional techniques. Associated with the program are independent databases with transport and thermodynamic properties of individual species. Over 1900 species are contained in the thermodynamic database. The program is written in ANSI standard FORTRAN by Bonnie J. McBride and Sanford Gordon. It is in wide use by the aerodynamics and thermodynamics community.

EQS4WIN is a powerful and easy-to-use software package that solves a wide range of problems related to the calculation of the reaction and phase equilibrium composition of complex chemical systems. EQS4WIN incorporates up-to-date technology in numerical analysis, programming, and thermodynamics. It was written under the supervision of Dr. W. R. Smith, senior author of a classic text in the field (see Ref. above). EQS4WIN solves equilibrium problems by minimizing the overall Gibbs free energy of systems involving up to 4 multi-species ideal-solution phases (a gas phase and up to 3 condensed liquid or solid solutions) and any number of pure (condensed) phases. Calculations can be performed for several different types of thermodynamic conditions, either at a single state point, or for up to two simultaneously varying parameters. All versions of EQS4WIN incorporate a thermochemical database based on the species listed in the JANAF Tables.

The Materials Thermochemistry Section at NPL (National Physical Laboratory, Teddington, Middlesex, UK) provides good quality thermodynamic data for an extensive range of material types. These data can be used to predict the chemical species and phases likely to form at equilibrium in the types of system of greatest industrial interest and so provide a valuable guide to the solution of many industrial problems. MTDATA is a software/data package for the calculation of phase equilibrium in multicomponent multiphase systems using, as a basis, critically assessed thermodynamic data (Davies R. H., Dinsdale A. T., Gisby J. A. MTDATA - Thermodynamic and Phase Equilibrium Software from the National Physical Laboratory // CALPHAD. – 2002. - V.26, 2. – P.229-271.). It has numerous applications in the fields of metallurgy, chemistry, materials science, and geochemistry depending only on the data available. Problems of mixed character can be handled, for example equilibrium in involving the interaction between liquid and solid alloys and matte, slag and gas phases. The thermodynamic models necessary to describe the properties of a wide range of phase types are incorporated in the software and database structures.

Over the past 25 years, OLI has refined software which accurately models multiphase, multicomponent aqueous solutions for virtually any mixture of chemicals. The basis for OLI’s Software is the "OLI Engine." The OLI Engine is made up of the Solvers and the software packages StreamAnalyzer, OLI Express, and the WaterAnalyzer.

The OLI Thermodynamic Framework provides accurate prediction of multicomponent aqueous systems including aqueous liquid, vapor, organic liquid, and multiple solid phases over the general range of 0 to 30 molal, -50 to 300 °C, and 0 to 1500 Bar. Computed thermodynamic properties such as pH, ionic strength, enthalpy, density, osmotic pressure are supplied automatically.

The OLI Databank contains thermodynamic, transport, and physical properties for 79 inorganic elements of the periodic table, and their associated aqueous species, as well as over 3000 organics. Thus, most mixtures of chemicals in water can be modeled, provided the solvent of the solution is water.

The Environmental Simulation Program (ESP) is a steady-state process simulator with a proven record in enhancing the productivity of engineers and scientists.  ESP provides the engineer or scientist accurate answers to questions involving complex aqueous systems.  The dynamic response of a process can be studied using the dynamic simulation program, DynaChem, to examine control strategy, potential upsets, scheduled waste streams, controller tuning, and startup/shutdown studies.

HSC Chemistry is made in Outokumpu Research Oy. However, many of the important calculation options are based on the code and ideas from other sources. The aim of this software is to simulate the chemical reaction equilibrium and processes in the personal computer in order to develop new processes and improve the old ones. HSC Database is a compiled database on thermodynamic properties of individual substances. The number of species in the database is more than 10000. These data are not critically evaluated, but give a fast access to data and references, which can be found from the literature. The database also has fields for Structural Formula, Chemical Name, Common Name, CAS number, melting point, boiling point, color and solubility to H2O. The data in these fields are not yet complete but even now they can help, for example, to identify organic substances.

Reaction Design of San Diego, California, USA, was founded in 1995 to provide software simulation and modeling tools to help process engineers create more efficient and environmentally friendly manufacturing processes.  In 1997, Sandia National Laboratories selected Reaction Design as the exclusive worldwide licensee for its CHEMKIN Collection and other software, which it had developed to aid in the design of processes that 
utilize chemical reactions. 

Reaction Design is focusing its development, consulting and marketing efforts on four chemistry-intensive process areas: 

·        Combustion: process heat and power generation, incinerators, jet and automotive engines, gas turbines and fuel design.

·        Chemical Processing: chemical and pharmaceutical, oil refining, paper, high performance materials, corrosion and lubrication, food flavors and fragrance.

·        Microelectronics Processing: integrated circuit manufacturing, semiconductor processing equipment and reactive precursors.

·        Environmental Protection: pollutant treatment and atmospheric chemistry.

 The flagship product of the company is CHEMKIN software

The CHEMKIN Collection facilitates the formation, solution, and interpretation of problems involving gas-phase and heterogeneous (gas-surface) chemical kinetics. The Collection's programs and subroutine libraries are flexible and powerful tools for incorporating complex chemical kinetics into simulations of reacting flow. CHEMKIN tools provide solutions for Combustion, catalysis, chemical vapor deposition, and plasma etching. 

The CHEMKIN Utilities consist of the Following Subroutine Libraries and Pre-processors: 

·        Gas-Phase CHEMKIN Pre-Processor and Subroutine Library for the analysis of gas-phase chemical and plasma kinetics.

·        Surface CHEMKIN Pre-Processor and Subroutine Library for the analysis of heterogeneous chemical kinetics at gas-solid interfaces

·        Thermodynamic Property Database containing polynomial fits to temperature for species enthalpy, specific heat, and entropy.

·        Transport Pre-processor and Subroutine Library for the evaluation of gas-phase, multi-component transport properties including diffusion coefficients, viscosities, and thermal conductivities of species and their mixtures.

·        Transport Property Database containing molecular parameters used in the calculation of transport properties.

·        TWOPNT numerical integration module for solving two-point boundary-value problems using a modified Newton iteration method.

Cosilab is a general combustion simulation tool that can be used to simulate a variety of laminar flames including, in some cases, radiating flames, droplets and sprays.  Cosilab supports all popular data formats for chemical reaction mechanisms, thermodynamic data and molecular transport data.

Within COSILAB, Run1dl is the core code that solves the equations governing laminar flamelets and flames.

A variety of different popular models for chemistry are implemented, including detailed mechanisms of elementary reactions, systematically reduced kinetic mechanisms, global one-step reaction models and the flame-sheet model for diffusion flames.

Similarly, various popular models of thermodynamics and molecular transport are implemented, ranging from detailed molecular models for thermal conductivities, dynamic viscosities and diffusion coefficients to simple constant-property models.

The models implemented for chemistry, molecular transport and thermodynamics can be overwritten by a user’s own models. To that end, the programming languages Fortran, C or C++ can be used.

Parts of the source code can be purchased, e.g., code that defines the discretized governing equations. Currently this is Fortran code. The user can modify, augment or eventually completely rewrite these portions of the code and hence adapt it to his particular physical problem at hand.

The Cosilab graphical user interface allows comfortable handling of the code. It manages input and output of data, pre- and postprocessing, and running the codes. Besides other features, it includes

·        a graph-digitizer for the generation of initial flame structures,

·        real-time display of evolving, transient flame structures, and

·        powerful graphing, editing and export facilities for the results.

Thermo-Calc is a powerful and flexible software for all kinds of thermodynamic and phase diagram calculations (Andersson J.O., Helander T., Hoglund T. THERMO-CALC & DICTRA, Computational Tools For Materials Science // CALPHAD. – 2002.-V.26, 2. – P.273-312.). It is specially designed for systems with strongly non-ideal phases. Thermo-Calc has been developed since 1981 by Bo Sundman (Prof, Head of Division of Computational Thermodynamics in  the Royal Institute of Technology, Stockholm, Sweden). The authors claim it is the only software which can calculate arbitrary phase diagram sections with up to five independent variables in multicomponent systems. There are also facilities to calculate many other types of diagrams for example CVD depositions, Scheil-Gulliver solidification simulations, partial pressures in gases etc.

Thermodynamic software is useless without accurate and validated databases. With Thermo-Calc it is possible to use databases from many sources using different models for each phase in a system. In particular there are the databases from SGTE (Scientific Group Thermodata Europe), a solution database with about 200 assessed systems and a substance database with about 3000 compounds. For special applications there are the IRSID database for slags, the Fe-base database for steels, the group III-V database for semiconductor materials, the Saxena geochemical database etc. The Thermo-Calc group has initiated and participates in many international projects in order to create a general and validated database. Any modern PC or workstation can be used for running Thermo-Calc. It has an interactive user interface and extensive documentation and on-line help facilities. Courses for students and industry are given three or four times a year. Thermo-Calc has a reactor simulator for process simulations and a documented programming interface for other simulation applications which need thermodynamic calculations for local equilibria and driving force calculations. There is also a module for assessment of experimental data within Thermo-Calc which provides the necessary means for extension of the databases. With Thermo-Calc one may simulate processes where the time-dependence can be ignored, for example by stepwise calculation of a sequence of equilibria with transfer of heat and matter between the equilibria.

Company Thermo-Calc Software was founded in 1997 as an offspring from the department of Materials Science and Engineering at KTH, Stockholm, Sweden. The aim was to further market and develop the Software for Computational Thermodynamics and for Diffusion Controlled Simulations, which had been developed at the department for more than 15 years. The company delivers software package Thermo-Calc.

Thermodynamic Data and Property Calculation Sites on the Web.