ChemApp

7.1 Why do I also need thermochemical data-files, is ChemApp itself not enough?

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To determine a chemical equilibrium, you need two things: A program which performs the necessary calculations (see section 6.1), which is what ChemApp does a data-file (also referred to as a ChemSage data-file) which contains the thermochemical data of all the phases and species in the chemical system you are investigating. ChemApp reads a thermochemical data-file […]

7.1 Why do I also need thermochemical data-files, is ChemApp itself not enough? Read More »

7.2 From where do I get these thermochemical data-files?

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Thermochemical data-files for ChemApp (and ChemSage, for that matter) can come from a variety of sources: ChemApp, as well as ChemApp light, comes with several example data-files for various chemical systems, which let you start gathering programming experience right away. These example data-files are also used for the code example which are part of the ChemApp

7.2 From where do I get these thermochemical data-files? Read More »

7.5 I’m trying to convert a data-file using ChemFile, but it crashes, what’s wrong?

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There are two common reasons for this effect: If the data-file is in ASCII form, check whether the line endings are correct. If the data-file has been copied from a different platform (e.g. from a DOS to a Unix machine), it could be that the line endings have not been converted properly. ChemFile only converts data-files from

7.5 I’m trying to convert a data-file using ChemFile, but it crashes, what’s wrong? Read More »

7.6 I have problems using binary data-files with ChemApp, what’s wrong?

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As you might know, ChemSage data-files come in ASCII, binary, and transparent flavors. Whereas ASCII data-files are portable between platforms and compilers, binary files are not. There is no Fortran standard with respect to binary files, the result is that a binary file created on one platform or compiler (e.g. with ChemSage or FACTWin) is in most cases

7.6 I have problems using binary data-files with ChemApp, what’s wrong? Read More »

7.7 How do I prepare data-files for ChemApp using FactSage?

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FactSage V5.0 and more recent versions can be used to create thermochemical data-files for ChemSage, and also for ChemApp and ChemSheet. The type of thermochemical data-file FactSage writes are called “transparent” data-files, and can be used with virtually all versions of ChemApp running under the Microsoft Windows operating system. Transparent data-files are usually not portable

7.7 How do I prepare data-files for ChemApp using FactSage? Read More »

6.1 How does ChemApp calculate the chemical equilibria?

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The technique employed by ChemApp to calculate complex, multicomponent, multiphase chemical equilibria is called Gibbs energy minimisation (GEM). An outline of this technique can be found in an article on ChemSage, which internally uses the same calculational engine as ChemApp [Eri90]. More information on the GEM technique can be obtained from the following references –   [Smi82] – W. R.

6.1 How does ChemApp calculate the chemical equilibria? Read More »

6.2 How is it possible that ChemApp calculates even complex equilibria so fast?

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Two main reasons can be given which are responsible for ChemApp’s speed: The GEM code has been under constant development for the last 30 years, since the days of SOLGASMIX. Along with the robustness of the code, its speed has always had a high priority. When ChemApp begins an equilibrium calculation, it tries to guess

6.2 How is it possible that ChemApp calculates even complex equilibria so fast? Read More »

6.3 Can I investigate time-dependent and kinetic phenomena with ChemApp?

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ChemApp itself does not contain any code to deal with kinetic issues, but the fact that ChemApp is available as an independent library makes it ideal to be used in programs that deal with these issues. In these cases, ChemApp is used to calculate a local equilibrium (“local” either meaning “local in time”, or “local

6.3 Can I investigate time-dependent and kinetic phenomena with ChemApp? Read More »