Tools for Converting Output from QM Calculations Into Something More Useful
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QMForge is a program used to analyze the results of quantum chemistry (DFT) calculations. Gaussian 98/03/09, ADF, GAMESS (US), GAMESS (UK), PC-GAMESS, Jaguar, NWChem, ORCA, and QChem files are supported (see below). The following analyses are available:

MPA, CSPA, LPA, and OPA require a user-defined set of fragments, and prints the percent contributions those fragments make towards each molecular orbital in the molecule. Mayer's bond orders calculates the bond orders between each pair of atoms in the molecule. CDA and Fragment Analysis require three or more calculations (one for the entire molecule, and two fragment calculations), and provide information about the bonding interactions between fragments.

QMForge can also be used to:



Pre-packaged binaries for Windows, Mac OS X, and some Linux distros (see below; others upon request) are available for $15 and will include minor updates. Your financial support will encourage further developement.

Mac OS X

Supported/tested Linux distros:

Older versions (prior to 2.2) and the Source Code can be found on the Sourceforge Project Page. Note that to install and run QMForge from source, you will need to install all of the dependencies listed in the next section.


QMForge has been created using the following dependencies:

QMForge has only been extensively tested on Mac OS X Snow Leopard and Mavericks, as well as Windows XP, with some minor testing on Yosemite. It should, however, work with Mac OS X Lion and Mountain Lion, and Windows 7 and 8.

If you do attempt to run and/or install QMForge from the Source Code, I cannot guarantee success with different version of those dependencies, and thus, will provide very limited support.

Since QMForge depends heavily on cclib for parsing files (and the calculation methods), check its documentation for any options in your QM package you may need to include. If you find a bug involving the parser or methods, please let me know and/or post to one of the cclib mailing lists.

QMForge can be cited however you feel appropriate, although I recommend ONE of the following:

  1. Tenderholt, Adam L. QMForge, Version 2.4, http://qmforge.sourceforge.net.
  2. Tenderholt, Adam L. "QMForge: A Program to Analyze Quantum Chemistry Calculations", Version 2.4, http://qmforge.sourceforge.net.

Of course, citation requirements vary from journal to journal, so adjust the above as necessary.

Bugs and New Features

QMForge depends on OpenBabel which doesn't always load correctly on some Windows XP systems. If you get an error like "DLL load failed: This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem." when trying to start QMForge on Windows, download and install the Microsoft Visual C++ 2005 Redistributable Package. You may also need to install OpenBabel.

If you find any other bugs PLEASE let me know, especially if you have purchased a binary copy. I'll try to fix it as soon as possible.

If you have a suggestion for other improvements, please let me know.


Version 2.4 (3/16/15) Version 2.3.2 (3/9/14) Version 2.3.1 (12/3/13) Version 2.3 (9/28/13) Version 2.2 (7/13/13) Version 2.2 beta (4/28/13) Version 2.1 (10/30/07) Version 2.0.1 (3/29/07) Version 2.0 (1/27/07) Version 1.5.2 (11/1/06) Version 1.1 (2/3/06):


QMForge is licensed under the GNU GPL. The source code can be found on the Sourceforge Project Page.

The GPL allows you to modify the program as you see fit, but if you distribute any of your changes (in binary or source form) you must state in any altered file when it was altered, provide the source code of your new version to anyone who requests it for a charge of no more than it costs you to send it to them, and license your work under the terms of the GNU GPL. This applies to all of the code, so you also can't include portions of QMForge in your own work without making your work subject to the terms of the GPL. Even if you decide to distribute an unmodified version, the recipients have the right to the source code so either provide it to them or direct them to this website.


QMForge is the direct descendent of PyMOlyze, which was inspired by the console-based, (originally) Windows-only program AOMix that has features including (and in addition to) those listed above. I initially wrote PyMOlyze in graduate school because I wanted a user-friendly (ie. graphical) Linux program to do MPA for each molecular orbital of Gaussian calculations.

QMForge was eventually extended it to handle files from geometry optimizations because I found myself wishing I could translate and rotate the optimized structure and save that as an XYZ file. During my Ph.D. program, I used QMForge for almost everything except making molecular orbital pictures and diagrams, however, now that I've moved on, it is more a hobby project. It now handles frequency and excited state calculations.

Last modified on 3/16/15
Adam Tenderholt
atenderholt at gmail dot com

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