[AZ.08.03.2025]
For conjugated molecules, the most commonly used density functionals are B3LYP, CAM-B3LYP, and ωB97X. Importantly, such parameters as BLA, conjugated dihedrals, bandgap, IE/EA, couplings [Sutton13] depends monotonically on the fraction of HF-exchange, so that typically B3LYP/ωB97X gives lower/upper estimates of these parameters, whereas CAM-B3LYP is the most accurate (polyacetylene, stilbene, distyrylbenzene derivatives, P3HT). For intra- and intermolecular noncovalent interactions, D3 dispersion corrections must be applied (D4 is yet to be implemented in mainstream DFT solvers). Since hybrid functionals are impractical for molecular crystals, PBE-D3 is the optimal trade-off between accuracy and scalability (BMCOS1 benchmark).