Automated Construction of Quantum–Classical Hybrid Models

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 that model describes atomic forces center accurately. This entails evaluation differently sized regions with bearable computational overhead needs to be paid validation procedures. Applying SFAM classical part eliminates any dependence pre-existing parameters due its mechanically derived parametrization. Hence, is capable delivering high fidelity complete automation. Furthermore, since generated whole system, ansatz allows convenient redefinition during molecular exploration. For purpose, local reparametrization scheme introduced, which efficiently generates additional fly when new covalent bonds formed (or broken) moved region.