Q-Chem

Q-Chem 7 features new super-fast NMR code! Q-Chem's new finite-difference NMR shielding code is up to 150x faster than previous versions when run in parallel (see the preliminary benchmarks in the attached figure), and it includes both OpenMP and MPI parallelization for vastly improved performance.

A paper associated with this development is still in preparation, but you can test it yourself today by requesting a free trial of Q-Chem 7: http://q-chem.com/try/

In this recent preprint, authors probe the effects of pressure and solvation in intermolecular charge-transfer excitations. They study the effects of donor-acceptor separation, investigate the effects of hydrostatic pressure, and benchmark both TD-DFT and ALMO-SGM approaches (both available in Q-Chem!) against experimental data. https://doi.org/10.26434/chemrxiv.15006527/v1

Try Q-Chem today: http://q-chem.com/try/

Q-Chem 7 includes OVOCV analysis for EDA and OO-DFT! OVOCV can be used to replace or complement NOCV analysis in EDA, providing clearer identification of donor and acceptor orbitals than NOCV methods. Check out the recent publication here: https://doi.org/10.1021/acs.jpca.4c02364

Try it yourself in Q-Chem 7: http://q-chem.com/try/

New in Q-Chem 7: CP2K interfacing! A new embedding interface for CP2K is now available for projection-based, pseudoperiodic wavefunction-in-DFT embedding; in this recent paper, authors use it to study aqueous chromophores. https://doi.org/10.26434/chemrxiv.15004875/v1

Try it today in Q-Chem 7: https://q-chem.com/try/

Did you miss Tuesday's webinar from Martin Head-Gordon on the latest developments in Q-Chem 7? Don't worry, we've got you covered—the recording is now available on our YouTube channel: https://youtu.be/5U7TDNGcpFU

Request a free trial of Q-Chem 7 today: http://q-chem.com/try/

Don't forget about today's webinar! Join us to learn about the latest features in Q-Chem 7, including new DFT and correlated methods, faster NMR, new EDA and XSAPT+MBD methods, and more. Register here: https://zoom.us/webinar/register/WN_oj2_EO1lTvG4-JY5enUWag

Interested in using Q-Chem's QM/MM interface with Amber? Check out our new tutorial (contributed by Yuezhi Mao) that provides a clear step-by-step process from beginning to end, using a chromophore–solvent system as a practical example. Read the tutorial here: https://www.q-chem.com/learn/qmmm_amber/

Check out our website for free Q-Chem webinars, workshops, labs, and other learning materials: https://www.q-chem.com/learn/

SAPT vs. EDA: How do they compare, and could they find some common ground?

This new preprint provides a side-by-side comparison of Q-Chem’s two popular energy decomposition analysis schemes. The authors focus on understanding what correlation, if any, exists between the schemes' respective energy components; they compare accuracy for a large set of biomolecular fragments and provide calibration plots to translate between SAPT+MBD and ALMO-EDA energy components. https://doi.org/10.26434/chemrxiv.15005476/v2

Try both energy decomposition schemes in Q-Chem 7 with a free trial: http://q-chem.com/try/

Q-Chem 7 includes a new MBD dispersion model for XSAPT+MBD: MBDrev! This model has revised MBD parameters for SAPT based on machine learning applied to the SAPT10k data set. It can be used with (X)SAPT to account for non-dispersion contributions and provides better performance than the previous (X)SAPT+MBD approach, including for large systems with hundreds of atoms.

Check out the paper from the developers: https://doi.org/10.1063/5.0204064

Try it yourself in Q-Chem 7: http://q-chem.com/try/

Our upcoming Q-Chem 7 webinar has been rescheduled for July 28th! Join us as Prof. Martin Head-Gordon reviews some of the latest and greatest features in Q-Chem 7, including DFT highlights, faster-than-ever NMR spectroscopy, unique analysis methods, and more.

Register here: https://zoom.us/webinar/register/WN_oj2_EO1lTvG4-JY5enUWag

We hope to see you there!