GaussSum requires Python, which is a programming language commonly used for scripting.
Go to the Python install page. Download and run the Windows installer for a recent version of Python 3 (e.g. Python 3.6).
GaussSum requires Numpy, which is a Python extension that allows efficient matrix algebra. You can install this with pip at the command-line: py -m pip install numpy
In order to draw the graphs, GaussSum requires the Python package Matplotlib. You can install this with pip at the command-line: py -m pip install matplotlib
In order to extract information from comp chem log files, the Python package cclib is need. You can install this with pip at the command-line: py -m pip install cclib
The scripts can be found here. Extract the zip file into something like C:\Program Files\GaussSum.
Create a shortcut on your desktop to GaussSum.py (to do this, right-click on an empty part of the desktop, choose New -> Shortcut, browse to the folder where you installed GaussSum and choose GaussSum.py). To change the icon, right-click on the icon, choose Properties -> General -> Change Icon -> Browse. Find the folder where you installed GaussSum and choose GaussSum.ico. In addition, change the program used to open GaussSum by following these instructions: right-click on the icon, choose Properties -> General -> Opens with -> Change -> PythonW. If you want to set a startup folder, right-click on the icon, choose Properties -> Shortcut -> Start in:, and type the name of the startup folder.
If you have any questions or requests, or if you wish to be added to the mailing list for information on new versions and bug fixes, please send an email to gausssum-help@lists.sourceforge.net.