Q-Chem

Q-Chem 7 is here! Read about the latest features, including new DFT functionals, numerical sparsity speedups, faster NMR, MRSF-TDDF, and more: q-chem.com/explore/qc7/ Request a free, month-long demo of Q-Chem and QC-PBC, free of charge: q-chem.com/try/ #compchem

Q-Chem 7 includes the first-ever extension of second-generation EDA to correlated methods: MP2, BW-s2, and κ-MP2! Try it with our new linear-scaling MP2 algorithm. doi.org/10.1021/acs.jc… Request a free trial of Q-Chem 7: q-chem.com/try/

New in Q-Chem 7: New charge-displacement metrics of TDDFT. This metric is rigorously invariant with respect to orbital rotations, unlike earlier metrics used in other software packages. Read the publication: doi.org/10.1021/acs.jc… q-chem.com/try/

Join us next week (July 21) for a webinar on the new features available in Q-Chem 7, our latest generational software release! Register today: zoom.us/webinar/regist…

New in Q-Chem 7: New CAP-DFT functionals! CAP-DFT, recently extended to GGA and derived hybrids, allows researchers to model energies and lifetimes of metastable molecular anions at an accuracy that rivals EOM-CC! doi.org/10.1021/acs.jp… Try Q-Chem 7: q-chem.com/try/

New in Q-Chem 7: Excited-state analysis for MRSF-TDDFT! This includes state and transition dipole moments, oscillator strengths, spin–orbit couplings, and density-matrix based analyses of MRSF states and transitions. doi.org/10.26434/chemr… Try Q-Chem 7: q-chem.com/try/

New in Q-Chem 7: Faster MP2 and double-hybrid #DFT! Our new linear-scaling local correlation algorithm provides competitive scaling with DLPNO, with improved error control for higher accuracy. pubs.acs.org/doi/10.1021/ac… Try Q-Chem 7 today! q-chem.com/try/

COACH is now available in Q-Chem 7! COACH is a new #DFT functional that is more accurate and transferable than the best existing RSH meta-GGAs, like ωB97M-V, for a variety of systems. Read the preprint here: doi.org/10.48550/arXiv… Try it in Q-Chem today: q-chem.com/try/

QC-PBC was recently used to model #electrochemistry at solid-liquid interfaces! Developers use grand canonical DFT alongside implicit solvent modeling to accurately model corrosion at silver surfaces. Read the preprint here: arxiv.org/html/2508.1570…

Last year, researchers developed regularized second-order perturbative (PT2) methods in QC-PBC for modeling solids. BW-s2 in particular provides accurate results for metals, semiconductors, and molecular crystals, and will be available in Q-Chem 7! pubs.acs.org/doi/10.1021/ac…

One of the things we're most excited about in Q-Chem 7 is QC-PBC: A new module that uses a GTO basis for modeling periodic systems. Highlights include fast hybrid DFT; CC and MP2; analytic derivatives; excited states; solvation; and EDA. Pre-order today: q-chem.com/purchase/

In this recent paper, authors used NPA charges in Q-Chem to obtain Fukui indices, which predict hotspots for different types of reactions; they used these results to rationalize the photodegradation products of chlortoluron, a common herbicide. doi.org/10.1016/j.jenv…

New in Q-Chem 7: Faster CC2 and CCSD with THC-sRI! Q-Chem developers recently combined their existing sRI framework in Q-Chem with tensor hypercontraction (THC) to provide accurate energy derivatives. arxiv.org/html/2509.0646… Preorder Q-Chem 7: q-chem.com/purchase/

Q-Chem 7 includes many improvements to CC2: * Large speedups for RI-CC2 ground state * CC2 and RI-CC2 Dyson orbitals for EA, IP, EE-EA, and EE-IP * RI-CC2 and sRI-CC2 oscillator strengths (read their paper: arxiv.org/html/2509.0646…) Pre-order Q-Chem 7! q-chem.com/purchase/

Q-Chem 6 has introduced several new CC methods, including EOM-CCSDT for high accuracy for EE, SF, IP, EA, DIP and DEA, implemented by Summer At Q-Chem intern Manisha. Watch the webinar about this work: youtube.com/watch?v=590rAd… Try Q-Chem today: q-chem.com/try/

New in Q-Chem 7: CAP-DFT! From author Charlotte Titeca: "[CAP-DFT] enables fast and accurate evaluation of the energies and lifetimes of metastable molecular anions. ...Hybrid functionals deliver results that are competitive with EOM-CC theory." pubs.acs.org/doi/10.1021/ac…

Q-Chem offers state-of-the-art tools for handling electron correlation, such as MP2 and CC methods; the Q-Chem 6 generation has included new correlated methods like EOM-CCSDT, BW-s2, TDDFT/TDA-SOC, and MRSF-TDDFT. Stay tuned as we highlight recent and upcoming features!

Researchers recently probed the origins of homochirality in biological systems and found that electron spin may be the key. Their conclusions are supported by EOM-EA-CCSD and Breit-Pauli SOC calculations in Q-Chem. iopenshell.usc.edu/pubs/pdf/sciad… Try Q-Chem: q-chem.com/try/

New in Q-Chem 7: Excited-state analysis based on Earth Mover's Distance (EMD)! This provides a new quantitative metric for characterizing charge-transfer in excitations. Read the paper from the developers: doi.org/10.1021/acs.jc… Pre-order Q-Chem 7: q-chem.com/purchase/

Q-Chem's Δ-ALMO(MSDFT2) combines ΔSCF with ALMO to generate diabatic states, then uses MSDFT2 to obtain their couplings with charge-transfer states. Here, developers test Δ-ALMO(MSDFT2) on systems ranging from singlet fission to DNA repair: doi.org/10.1063/5.0035…