We present a protocol for the fully automated construction of quantum mechanical (QM)–classical hybrid models by extending our previously reported approach on self-parametrizing system-focused atomistic (SFAMs) [Brunken, C.; Reiher, M. J. Chem. Theory Comput. 2020, 16, 3, 1646?1665]. In this QM/SFAM approach, size and composition QM region are evaluated in an manner based first principles so th...