Q-Chem

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)

Check out this recent preprint from developers, where they extend ALMO-EDA to QC-PBC and use it to study non-bonded interactions in solids: https://arxiv.org/pdf/2605.15381
QC-PBC comes bundled with Q-Chem 7.0, which will be released in July! Pre-order today: https://q-chem.com/purchase/

Check out this recent paper! Authors used natural population analysis (NPA) charges in Q-Chem to obtain Fukui indices, which predict hotspots for different types of reactions; this allowed them to rationalize photodegradation products of chlortoluron, a common herbicide. https://doi.org/10.1016/j.jenvman.2026.130150