Q-Chem Newsletter: June 2026

Q-Chem News & Events

Q-Chem 7: Coming Soon!

Q-Chem 7 is coming in July 2026! Q-Chem 7 includes all of the performance and usability features you've come to expect from Q-Chem (like our parallel RI algorithms for fast DFT performance, and our Robust SCF algorithm for easy convergence), along with a plethora of new features.

Get a sneak peek at some of our highlighted features here! ⧉

Feature of the Month: QC-PBC

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. Key features include:

• DFT: Optimized parallel performance that leverages Q-Chem's fast integral libraries; includes hybrid functionals
• Post-HF Methods: MP2, LT-MP2, and MP3; BW-s2; dRPA; CCSD, CCSD(T), and CCSDT
• Excited-state Methods: CIS and TDDFT
• Analytic frequency and phonon calculations
• Scalar and relativistic effects
• Solvation effects
• Energy decomposition analysis (EDA)

A recent paper highlight: Authors recently developed several regularized second-order perturbative methods in the QC-PBC package, including BW-s2, which provides accurate results for metals, semiconductors, and molecular crystals. Read the paper here. ⧉

Pictured on the right: Comparison of cohesive energy (eV) calculated for the benzene crystal. Citation: arXiv:2508.15744

Recent Publication Highlights

CAP-DFT for Modeling Metastable Anions

Density Functional Theory with Complex Absorbing Potentials: A Fast and Accurate Way of Modeling Metastable Anions. ⧉ Charlotte Titeca, Yifan Jiang, Frank De Proft, and Thomas-C. Jagau. J. Phys. Chem. Lett. 2026.

New in Q-Chem 7: CAP-DFT! This new approach provides a great way to model metastable molecular anions. Check out this recent paper from the developers. ⧉

From Charlotte Titeca, one of the authors: "We report an implementation of CAP-DFT and complex-variable density functional approximations up to the generalized gradient approximation and derived hybrid functionals, which enables fast and accurate evaluation of the energies and lifetimes of metastable molecular anions. This new method is applied to various molecular systems, including the metastable anions of molecular nitrogen, formaldehyde, formic acid, ethene, and pyrene. Hybrid functionals deliver results that are competitive with equation-of-motion coupled-cluster theory."

CAP-DFT will be available in Q-Chem 7, which is coming out in just a few weeks.

Interactions in Solids: ALMO-EDA for QC-PBC

Chemical Origins of Non-Bonded Interactions Within and Between Solids. ⧉ Paul J. Robinson, Adam Rettig, Hieu Q. Dinh, Anton Z. Ni, and Joonho Lee. Preprint (arXiv). 2026.

In this recent preprint, the developers of QC-PBC extend ALMO-EDA to solid-state systems. They use this approach to study non-bonded interactions in solids, including molecular crystals, moiré heterobilayers, and layered perovskite heterostructures. They glean useful insights that allow them to approach materials design with clear, chemically-intuitive understanding. Read their preprint here! ⧉

Modeling Electrochemistry at Solid-Liquid Interfaces

Gaussian-Based Periodic Grand Canonical Density Functional Theory with Implicit Solvation for Computational Electrochemistry. ⧉ Anton Z. Ni, Adam Rettig, and Joonho Lee. Preprint (arXiv). 2025.

QC-PBC was recently used to model electrochemical reactions at solid-liquid interfaces! Developers introduced a numerical method for grand canonical density functional theory (DFT) for periodic systems in QC-PBC and then used their implementation, along with their implicit solvent modeling implementation, to model corrosion at silver surfaces. You can read more in the preprint here. ⧉

Probing The Origins of Homochirality with Q-Chem

Dynamic breaking of mirror symmetry in spin-­dependent electron transport through chiral media causes enantiomeric excesses. ⧉ Yossi Paltiel, Daniel Goldberg, Nir Yuran, Shira Yochelis, Jia Hao Soh, Christopher Seibel, Jürgen Gauss, Shmuel Zilberg, S. Furkan Ozturk, Jonas Fransson, Anna I. Krylov, and Ron Naaman. Sci. Adv. 2026.

Homochirality is key in biological systems—for example, DNA is a right-handed helix—but questions about why life is homochiral, and why a specific handedness is favored, are still hotly debated.

In this recent paper, authors leverage quantum chemistry calculations alongside direct experimental measurements to probe the origins of homochirality in biological systems. Their results indicate that electron spin may be the key: Chirality can affect the efficiencies of spin-related processes, providing an advantage for one handedness over the other.

The main thesis of the paper was supported by EOM-EA-CCSD calculations of chiral molecules and all-electron calculations of Breit-Pauli SOC, enabled by Q-Chem.

Additional Publication Highlights

For the most up-to-date paper highlights, follow us on LinkedIn, X, or BlueSky! Want to see your recent paper or preprint featured on our social media posts or in our newsletter? Submit suggestions using our form here!