CHEMRev v. 1.30 (Sept. 2004)

CHEMRev is a user-friendly application, written in Visual Basic, that:

  • calculates the specific heat (Cp/R), the enthalpy (H0/R) and the entropy (S0/R) of a species at any given temperature.
  • computes the reverse rate constant of reactions
    C + D = > A + B with parameters: Ar, nr and Er from the Arrhenius equation kr = Ar Tnr exp(-Er/RT),
    given Af, nf and Effrom kf = Af Tnf exp(-Ef/RT) for A + B =">" C + D and a convenient thermodynamic database.
  • is part of the suite of software tools for the comparison of detailed reaction mechanisms and rounds out CHEMDiffs.

Nota Bene: You must use a full stop "." as the decimal point and not a comma "," in your input files. And you must reset your computer via "Control Panel/Regional Options/Numbers" to Decimal Symbol="full" stop.


Unzip the downloaded, and launch "setup.exe". You may be required to restart your computer.

We have successfully tested the application on a number of PCs (mainly Windows 98, 2000 and XP). However, downloading and installing are done entirely at your own risk.

Email with your details if you want to be notified of updates.


Use the function "Add/Remove Programs" from your Control Panel.

How Does CHEMRev Work?

You need to provide the filename of a CHEMKIN thermodynamic database (14 coefficients); which looks like this:

  • You need to provide the filename of a CHEMKIN mechanism ("cleaned" by CHEMClean beforehand).


  • You can also provide the filename of a CHEMDiffs output file, usually called "common.txt". CHEMRev will automatically complete the comparison between 2 mechanisms, calculating the reverse rate constant coefficients of reactions written in opposing direction in the opposing mechanisms. Results of the process are directly typed within the loaded file.

  • By default, CHEMRev searches the thermodata and locates the smallest, most inclusive, temperature range [T(low),T(high)], over which it will compute N values (default N is 50) of the reverse rate constant. However, you can modify the following settings:
    • the temperature range from T(low) to T(high).
    • the number of intervals (3<N<10000). Note that the bigger N, the slower the programme.
    • the model used to fit the data: traditional or extended Arrhenius equation.

  • The reverse rate constant coefficients can be calculated
    • for one particular reaction. Select one reaction in particular and click on Reverse. Results are copied in "temp.txt".
    • for some reactions selected in the list. Select several reactions using the key "Ctrl" of your keyboard and click on Reverse Selected. Results are copied in an output file named"RevfileSel.txt".
    • for all the reactions of the uploaded mechanism. Click on Reverse All. This operation might take some minutes, depending on the number of reactions in your mechanism. Results are copied to an output file named "RevfileAll.txt".

That's it! Use Button Quit to exit.


Optional: If you have got a large mechanism and want to find a particular reaction. Click on ?

A window pops up:

  • displaying alphabetically sorted list of reactions.


  • specify the name of some species in the reaction that you are seeking, then click on Begin Search.

Once you have found the reaction that you were looking for, double-click on it to return on the main window.