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. To apply to become a developer, contact support@q-chem.com. New developers will be asked to sign a non-disclosure agreement pledging to respect the intellectual property of other developers by protecting the code from unauthorized access.



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).