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How Q-Chem Got Started

Q-Chem software is distributed by Q-Chem, Inc., a software company based in Pittsburgh, Pennsylvania, USA. It was founded in 1993 as a result of disagreements within the Gaussian company that led to the departure (and subsequent “banning”) of John Pople and a number of his students and postdocs (see Gaussian License Controversy.)

The first lines of the Q-Chem code were written by Peter Gill, at that time a postdoc of John Pople, during a winter vacation (December 1992) in Australia. Peter Gill was soon joined by Benny Johnson (a Pople graduate student) and Carlos Gonzalez (another Pople postdoc), but the latter left the company shortly thereafter. In mid-1993, Martin Head-Gordon, formerly a Pople student, but at that time on the Berkeley tenure track, joined the growing team of academic developers.

Today Q-Chem has grown to involve more than 100 developers in 9 countries around the world. You can read more detail about Q-Chem's history here.


Developers: Please sent your achievements and successes to marysue@q-chem.com

Current Q-Chem News



Congratulations to Q-Chem developer, Anna Krylov, who has received the Mildred Dresselhaus Award 2017 at the University of Hamburg in Germany. She was honored for her outstanding contributions to electronic-structure theory, particularly for the development and application of powerful coupled-cluster-based methods. The prize includes research stays in Hamburg, where Anna Krylov will collaborate with Robin Santra from the Center for Free-Electron Laser Science, in particular, and other groups.

(January 2018)


Congratulations to developer Prof. Dr. Christian Ochsenfeld (University of Munich) who has been elected to the International Academy of Quantum Molecular Science. http://www.iaqms.org/news.php

(August 2017)


Congratulations to developer Prof. Troy Van Voorhis (MIT) who has been awarded the 2017 Anual Medal from International Academy of quantum Molecular Science "For the development of new theories and algorithms, including constrained density functional theory and van der Waals functionals, which have expanded the impact of quantum chemistry." http://www.iaqms.org/news.php

(August 2017)


Congratulations to Dr. Andrew Gilbert who is to be awarded Developer of the Year Michael Wormit Award which recognizes excellence in the development of new methods and algorithms in the area of electronic structure and implementing these methods in state-of-the art computer codes within the Q-Chem open teamware community project. An award dinner is planned for August in Munich.

(March 2017)



In conjunction with the WATOC 2017 in Munich, Germany (27 Aug. - 1 Sept 2017), we would like to announce a Q-Chem Developers’ Meeting/Workshop to take place on Saturday afternoon, Aug. 26 (exact time and location TBA). The meeting will be free of charge, with food and refreshments provided (but lodging arrangements on you own). The Developer's workshop will be following by the Michael Wormit Award reception and dinner.

In order to get a head count for catering purposes, please send a message to office@q-chem.com if you expect to attend and/or send students and postdocs.

It is our aim to hold a Developers’ Meeting approximately annually. We hope that you can attend this one, and provide you input as to the future of the code!

(March 2017)


Congratulations to Dr. Evgeny Epifanovsky for receiving Developer of the Year Michael Wormit Award which recognizes excellence in the development of new methods and algorithms in the area of electronic structure and implementing these methods in state-of-the art computer codes within the Q-Chem open teamware community project. Many thanks to everyone who joined the award dinner in San Diego.

(March 2016)

Congratulations to Anna Krylov has been was elected a a 2015 Fellow of the American Chemical Society.

(July 2015)

Congratulations to Anna Krylov has been was selected (as one of 100 women) to be recognized by the INSIGHT Into Diversity 2015 Inspiring Women in Stem Award, in the upcoming September STEM issue of INSIGHT Into Diversity magazine.

(June 2015)

Congratulations to Peter Gill, Arieh Warshel, and Anna Krylov who have been elected into International Academy of Quantum Molecular Science (http://www.iaqms.org).

(June 2015)

Q-Chem Establishes The Michael Wormit Award - established to recognize excellence in the development of new methods and algorithms in the area of electronic structure and implementing these methods in state-of-the art computer codes within the Q-Chem open teamware community project. The award, which will be given annually, includes a certificate and $500 prize. It commemorates contributions of Dr. Michael Wormit who is remembered for his state-of-the-art developments of many-body methods, for his leadership in the community, for his educating and mentoring of junior team members, and for his infrastructure development.

(May 2015)


Congratulations to Q-Chem developer and Scientific Advisor, Prof. Martin Head-Gordon, on his election as a member of the National Academy of Sciences! (April 2015)


Congratulations to Q-Chem developer, Joe Subotnik, on winning the Cottrell Scholar award! (May 2014)


Congratulations to Q-Chem developer, Arieh Warshel, on winning the 2013 Nobel Prize for Chemistry! (Oct. 2013)



Congratulations to Q-Chem developer Prof. Lyudmila Slipchenko who has been elected to join the Board of Directors of the International Society of Theoretical Chemical Physics. (Aug. 2013)



Congratulations to the seven Q-Chem developers who have just been recognized on the website, "Women in Theoretical Chemistry":

Ksenia Bravaya, Debashree Ghosh, Cherri Hsu, Anna Krylov, Adele Laurent, Wanzhen Liang, and Lyudmila Slipchenko. (Aug. 2013)



Congratulations to Q-Chem developer Alan Aspuru-Guzik who received tenure at Harvard University. (Apr. 2013)



Congratulations to Q-Chem developer Johannes Hachmann who just won the 2013 ACS Physical Chemistry Division Postdoctoral Award. (Apr. 2013)

UC Riverside


Congratulations to Q-Chem developer Greg Beran who just got his tenure at University of California at Riverside. (Apr. 2013)



Q-Chem would like to congratulate our developer Dr. Ksenia Bravaya who is joining Boston University in the Fall 2013 as an Assistant Professor. (Mar. 2013)



Congratulations to Q-Chem developer, Dr. John Parkhill, who is joining University of Notre Dame in the Fall 2013 as an Assistant Professor. (Mar. 2013)

John Herbert


Q-Chem board member, John Herbert , has received the Inaugural Journal of Physical Chemistry Lectureship Award for JPC-A (to be awarded at the ACS National meeting in Indianapolis). This is awarded to chemist who has had a major impact in the field of physical chemistry research within ten years of earning their Ph.D. (Feb. 2013)

Peter Gill


President of Q-Chem, Peter Gill, will receive the 2013 Fukui Medal of the Asia-Pacific Association of Theoretical and Computational Chemists (APATCC). Congratulations! (Jan. 2013)



Recent Publications


Here are the latest papers citing either the Q-Chem 2.0 paper and/or the Q-Chem 3.0 paper. Earlier publications can be found here.

News Archive




  • Announcing IQmol!
    Q-Chem is proud to recommend IQmol as its preferred molecular editor and visualization package. IQmol is a free open-source program which offers a range of features that include a molecular editor, surface generation (orbitals and densities) and animations (vibrational modes and reaction pathways).

    IQmol has been integrated with Q-Chem and features an intuitive environment to set up, run and analyze Q-Chem calculations. For more information about IQmol as well as downloading information visit www.iqmol.org.

  • Harvard Clean Energy Project - Powered by Q-Chem
    Q-Chem was recently informed by Harvard that their Clean Energy Project was largely the result of "nearly 40 million DFT calculations with Q-Chem."

    The Harvard Clean Energy Project, motivated by the ever-growing energy crisis, mounts an extensive search for promising photovoltaic organic material which might result in a cheaper and more efficient source of harvesting solar power.  Candidates for photovoltaic applications are screened through molecular calculations performed on more than a million computers, to first eliminate unfit material and provide for structural tends among promising candidates, as well as to examine and provide a more detailed characterization of promising molecules.

    Read more about the Clean Energy Project here.

  • In April of 2011, Professor Martin P. Head-Gordon, Scientific Advisor to Q-Chem, was elected to the Chemistry Section (Class I, Section 3) of American Academy of Arts and Sciences. [Pdf Announcement]

  • Professor Peter Gill, President and contributing developer of Q-Chem, has been awarded the 2011 Schroedinger Medal of the World Association of Theoretical and Computational Chemists (WATOC) for "his outstanding contributions to intracules, Coulomb operator resolutions, perturbative techniques, and two-electron system".



  • Dr. Chao-Ping Hsu, contributing developer of Q-Chem, was awarded the 2010 Pople Medal for "her contributions to charge transport and energy transfer in advanced materials and dynamic description of biological systems. She developed computational schemes to characterize the electronic coupling strengths for both electron transfer, excitation energy transfer processes, and ab initio computational schemes to calculate triplet excitation energy transfer."





  • Dr. Anna I. Krylov, Board Member and contributing developer of Q-Chem, was awarded the 2007 Agnes Fay Morgan Research Award, Iota Sigma Pi National Honor Society

  • March, 2007 - Q-Chem Launches Version 3.1 Software


  • Dr. Anna I. Krylov, Board Member and contributing developer of Q-Chem, was awarded the 2006 Dirac Medal for "her outstanding research on new methods in electronic structure theory for the description of bond-breaking, in particular the spin-flip method."

  • March, 2006 - Q-Chem Launches Version 3.0 Software


  • March 15, 2004 - The Board and Employees of Q-Chem, Inc. were saddened by the recent death of Professor John Pople. John has been a director of Q-Chem for the last five years and we thank him for all that he has done for us, both as individuals and as a company. He will be greatly missed by his friends and by the scientific community to which he contributed so much.