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The Chemical Reaction Network Toolbox Version 1.1: Downloads and Instructions

Two Notes Added in January, 2011:

(A)  You can now access a Windows version of the Toolbox -- Version 2.X --  here: CRNT WIN. See, however, note (B).

(B)  The old DOS version, described below, retains considerable capabilities that the Windows version lacks, notably its simulation environment. The DOS version can be run on modern Windows computers, on Macs, and on Linux machines after installation of DOSBox, which is available here: DOSBox.  For most theoretical analyses of reaction networks, however, the Windows version is far more powerful.

IMPORTANT NOTE:  The current "official" version of The Chemical Reaction Network Toolbox remains Version 1.02. However,  we are making available a "beta" copy of Version 1.1, primarily for readers of articles that have recently appeared in The Journal of Molecular Catalysis A.  Version 1.1 has advanced capabilities in the Network Analyst part of the program, capabilities that are helpful in mechanism discrimination when multiple pathways are believed to be operative. (In more technical terms, Version 1.1 implements certain tools of reaction network theory, resulting largely from Phillipp Ellison's Ph.D. work, that extend the older deficiency one theory substantially beyond the class of deficiency one networks.)  For most users, Version 1.02 is the one to get, but users who wish to try the "beta" copy of Version 1.1 are welcome to do so. Version 1.1 was adapted by Phillipp Ellison from the code written by Martin Feinberg for Version 1.02.   Instructions for downloading both versions are at end of this page.

Some General Information about The Chemical Reaction Network Toolbox

     The Chemical Reaction Network Toolbox (CRNT) is a DOS program for personal computers. It will run (as a DOS program) on Windows 95 and later. CRNT does many, many things. People who use the program tell me that it's very easy to use and that they like it a lot. CRNT should be of interest to chemists, chemical engineers and mathematicians at all levels of expertise (ranging from undergraduates to those engaged in very advanced research).  I know that CRNT will provide chemical engineering students with lots of help with their kinetics homework! 

    The program consists of two parts, ChemLab and Network Analyst, that "talk to each other".  ChemLab is the part of CRNT that will probably be of interest to most users, so I'll describe that first.  ChemLab is essentially a simulation environment. In response to a user-specified network of chemical reactions (and a user-specified assignment of rate constants), ChemLab will generate the appropriate (isothermal mass action) system of ordinary differential equations governing the species concentrations.  (These differential equations will generally be nonlinear and can be very complex.)  In response to user-specified initial conditions, ChemLab will solve the differential equations and display the results in a variety of numerical and graphical formats. In particular, ChemLab will plot species concentrations vs. time and will draw two- and three-dimensional composition trajectories.  ChemLab will also draw several trajectories simultaneously so that you can see two- and three-dimensional phase portraits. 

    Network Analyst, on the other hand, is somewhat more advanced.  It implements certain results in chemical reaction network theory. Chemical reaction network theory deals with the relationship between reaction net- work structure and qualitative properties of the corresponding differential equations. For example, in response to a user-specified reaction network, Network Analyst will try to determine if there can be rate constants such that the resulting differential equations admit composition oscillations, an unstable steady state, multiple steady states, a degenerate steady state (i.e., one with a zero eigenvalue), and so on.  When the Network Analyst determines that the answer is NO, it will tell you so.  On the other hand, if Network Analyst determines, for example, that a reaction network has the capacity for multiple steady states, it will exhibit a sample set of rate constants along with a pair of steady states consistent with them. (The rate constants and the steady states can be exported to ChemLab for further study.)  It should be mentioned in particular that Network Analyst provides powerful tools for mechanism discrimination in heterogeneous catalysis. 

     CRNT comes with an on-screen tutorial and a help system that get you up and running pretty quickly. (Or so I'm told.) The tutorial was written primarily with chemical engineers and chemists in mind, but there's an appendix for mathematicians who want to understand how the differential equations come about. Again, ChemLab is probably the part of CRNT that will be of interest to most users, so it's probably best to concentrate on that first. 

Best wishes,
Martin Feinberg

Downloading and Unpacking

Unpacking Instructions: The purpose of these instructions is to tell you how to use the file CRNTPACK.ZIP, which contains everything you need to get going.  (If you choose to download Version 1.1, then the file will be named CRNTPK11.ZIP, but the instructions are analogous. In this case, the name of the executable program is CRNT11a.exe, not CRNT.exe.)

    CRNTPACK.ZIP contains all the REAL files you need to run CRNT. You should make a directory (for example c:\CRNTDIR) to contain all your CRNT files.  Make sure to extract all the files contained in the zip file to your chosen directory, in particular the main program file CRNT.EXE. (You should always operate CRNT from the directory you created because the program will look there for the files it needs.)

    If you now enter the command CRNT at the DOS prompt, the main program will begin to run. There's an on-screen tutorial, "Hello, New User!", that you can select from the main menu. It's a good idea to get a printout -- the on-screen tutorial will tell you how -- so that you can follow the examples more easily. The printed tutorial is fairly brief (about 25 pages of easy reading).

To download The Chemical Reaction Network Toolbox, Version 1.02a click here: CRNTPACK.ZIP(391 KB)

To download The Chemical Reaction Network Toolbox, Version 1.1a click here: CRNTPK11.ZIP. (486 KB)