About Q-Chem

Q-Chem, Inc. is a comprehensive ab initio quantum chemistry program to solve computational problems faster, more accurately and less expensively than ever before possible. Q-Chem's capabilities facilitate applications in pharmaceuticals, materials science, biochemistry and other fields.  Q-Chem also provides users with the highest level of technical support. Q-Chem was established in 1993, and there have been five major releases to date.

Thousands of Q-Chem installations are in use worldwide. In addition, more than 55,000 licensed copies of Q-Chem have been sold as a tightly coupled interface to Wavefunction, Inc.'s Spartan graphical user interface. Citations of the Q-Chem papers topped 400 per year in 2016, and continue to increase (as reported by ISI Web of Science). 


Q-Chem Citations




About Open Teamware


Q-Chem is an open-teamware project. The source code is open to a large group of developers (currently more than 100 individuals in 9 countries), who can check in features to appear in official releases as long as they do not violate the integrity of the code and are scientifically sound. Click here to find out more about joining our developer community.



Developer Activity
Statistics of Q-Chem developer activity since 2006. Top chart: Total number of code commits (height of bars) and number of developers contributing (color of bar) by month. Bottom chart: Growth of developer base, showing existing and new developers each month. A steady growth of the developer base can be seen. The inset depicts the total number of commits by the 50 most-prolific developers, showing contributions by full-time team members (> 2000 commits), the core developer team (500–2000 commits), and non-core developers (< 500 commits).