Q-Chem

New in Q-Chem 7: Faster MP2 and double-hybrid DFT! A new numerical sparsity algorithm provides competitive scaling with DLPNO for MP2 and double-hybrid DFT, with improved error control for higher accuracy. Check out the recent JCTC paper: https://pubs.acs.org/doi/10.1021/acs.jctc.5c01358

This feature can be turned on in Q-Chem 7 for double-hybrid functionals using the "DH_PT2_ENGINE = LMP2" keyword.

Try Q-Chem 7 today! https://www.q-chem.com/try/

The COACH functional is now available in Q-Chem 7! COACH is a new range-separated hybrid (RSH) meta-GGA that is more accurate and transferable than the best existing RSH meta-GGAs, such as ωB97M-V, for a wide variety of systems.

Read the preprint here: https://doi.org/10.48550/arXiv.2603.23466
Try it in Q-Chem today: http://q-chem.com/try/

Q-Chem 7 is here! It includes all of the performance and usability features you've come to expect from Q-Chem, along with a plethora of new features, including the COACH functional; linear-scaling MP2 and double-hybrid DFT; MPI-enabled NMR features; MRSF-TDDFT energies and properties; and much more!

We are also excited to introduce QC-PBC, a new module for GTO-based ab initio materials modeling, available now! We will also release M-Chem, a module for molecular dynamics and biological systems modeling, later this month.

Read about some of our highlighted Q-Chem 7 features: https://www.q-chem.com/explore/qc7/
Request a free, month-long demo of Q-Chem and QC-PBC, free of charge: https://q-chem.com/try/

Modeling solids with MP2 often suffers from divergence or overcorrelation issues. Last year, researchers developed several regularized second-order perturbative methods in the QC-PBC package: κ-MP2, σ-MP2, and BW-s2. Their benchmarks demonstrate that BW-s2 provides accurate results for metals, semiconductors, and molecular crystals, doing just as well as (and in many cases, better than) CCSD at lower computational cost.

Read the paper here: https://pubs.acs.org/doi/10.1021/acs.jpclett.5c02731

BW-s2 for periodic systems is available in our new QC-PBC package, which will be released as part of Q-Chem 7 in just a few weeks! Pre-order QC7 today to save on licensing fees: http://q-chem.com/purchase/