The of VDD ligand charges and reaction energies is slightly improved for different-sized saaPCVA-constructed QM regions compared to distance-based construction of the QM region. Also sensitivity convergence calculated with the global PCVA approach is slightly better for PCVA-constructed regions. The assessment of atomeconomical QM regions constructed from standard and cryst PCVA and the comparison to a 12-residue QM region constructed based on the CDA approach from Bash et al.