quantum mechanics/molecular mechanics (QM/MM)

Also contains definition of: QC/MM
https://doi.org/10.1351/goldbook.QT07469
Hybrid procedure for the treatment of large molecular systems. A crucial part of the system (e.g., the @C01076@ and its surroundings) is treated explicitly by quantum mechanical (QM) techniques, whereas the rest of the system is approximated by a classical or molecular mechanics (MM) force field treatment.
Note:
Sometimes called QC/MM.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 406 [Terms] [Paper]