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Q-Chem 5.1:
Facilitating Worldwide Scientific Breakthroughs

Q-Chem is a comprehensive ab initio quantum chemistry package for accurate predictions of molecular structures, reactivities, and vibrational, electronic and NMR spectra. The new release of Q-Chem 5 represents the state-of-the-art of methodology from the highest performance DFT/HF calculations to high level post-HF correlation methods:

  • Fully integrated graphic interface including molecular builder, input generator, contextual help and visualization toolkit (See amazing image below generated with IQmol; multiple copies available free of charge);
  • Dispersion-corrected and double hybrid DFT functionals;
  • Faster algorithms for DFT, HF, and coupled-cluster calculations;
  • Structures and vibrations of excited states with TD-DFT;
  • Methods for mapping complicated potential energy surfaces;
  • Efficient valence space models for strong correlation;
  • More choices for excited states, solvation, and charge-transfer;
  • Effective Fragment Potential and QM/MM for large systems;
  • For a complete list of new features, click here.


IQmol: The smart choice in molecular visualization software!

The above image, generated in IQmol, shows the lowest unoccupied molecular orbital (LUMO) for the 12-crown-4 ether complexed with a lithium cation. The mesh superimposed on the system shows the total density.


BrianQC speeds up Q-Chem by calculating time consuming steps on your GPU.

BrianQC is a new quantum chemistry software which fully exploits the computational power of GPU's. Its innovative compiler technique will speed up your simulations by making your Q-Chem software run on GPU’s. BrianQC is the first GPU quantum chemistry software capable of calculating high angular momentum orbitals (f and g) as well, and it is highly efficient for simulating large molecules and quantum systems.

Q-Chem is available a stand-alone package with a fully integrated graphic interface IQmol. It also serves as the back-end of Spartan:

Spartan '18: The latest addition to Wavefunction’s line of molecular modeling software for research and education!

Spartan '18:  Enhanced, Refined, and Faster than ever. The Parallel Suite includes utilization of up to 16 cores for select tasks as well as the Spartan Spectra and Properties Database, and the ability to act as a Computational Server for jobs submitted from other Spartan Parallel Suite, Spartan licenses, or iSpartanapps (on the iPad, iPhone, or iPod Touch).
For more information click visit

Q-Chem News & Events

  • Q-CHEM 5.1 HAS BEEN RELEASED!  Click here to see our release log.
    Upgrade today!

  • Want to learn more? A Q-Chem Workshop will be held in Sydney, Australia in coordination with the APATCC 2019 conference on September 29, 2019.
    For more information see here.

  • Q-Chem is proud to be the engine behind several major energy projects in the US:
    • The Harvard Clean Energy Project, conceived to search for viable materials that might become the future of renewable and sustainable solar energy, has performed computational studies of millions of compounds, powered by Q-Chem. Read more about this exciting project here.

    • In JCSER's high-throughput screening for new electrolyte materials for batteries/energy storage project, their Electrolyte Genome software interfaces with Q-Chem to perform automatic DFT calculations in large numbers. Read more about it here.

    Developer News

  • Q-Chem will soon be announcing our call for interest in our 2019 Summer Internship program. Learn more about it here.

  • We are now accepting nomination submissions for The Michael Wormit Award which has been 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. For more information about eligibility and selection criteria, please click here. Nominations should be sent to with the subject "Wormit Award Nomination" by February 15, 2019. The award winner will be announced soon thereafter and the award will be presented at the ACS meeting to be held in San Diego in August 2019.

  • Congratulations to Q-Chem developer, Debashree Ghosh, who has received PCCP Emerging Emerging Investigator Lectureship Award!

  • Congratulations to Q-Chem developer, Dr. Ka Un Lao (Postdoctoral Associate under Prof. Robert DiStasio at Cornell University) who has won the Wiley Computers in Chemistry Outstanding Postdoc Award!

  • Congratulations to Prof. Anna Krylov (University of Southern California) who has received the highly competitive 2018 Simons Fellowship in Theoretical Physics. More information on this award can be found here. Congratulations!

  • Congratulations to Q-Chem developers, Prof. Martin Head-Gordon (University of California at Berkeley) and Prof. Dr. Christian Ochsenfeld (University of Munich) on being elected to the WATOC Board. Prof. Head-Gordon has also been voted President Elect of the WATOC Board. Congratulations!

  • Visit our News Page for more news about our company and our developers.