Article · Wikipedia archive · Last revised Jun 21, 2026

ONIOM

The ONIOM method is a computational approach developed by Keiji Morokuma and co-workers. ONIOM is a hybrid method that enables different ab initio, semi-empirical, or molecular mechanics methods to be applied to different parts of a molecule/system in combination to produce reliable geometry and energy at reduced computational cost.

Last revised
Jun 21, 2026
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The ONIOM (short for 'Our own N-layered Integrated molecular Orbital and Molecular mechanics'1) method is a computational approach developed by Keiji Morokuma and co-workers. ONIOM is a hybrid method that enables different ab initio, semi-empirical, or molecular mechanics methods to be applied to different parts of a molecule/system in combination to produce reliable geometry and energy at reduced computational cost.234

The ONIOM computational approach has been found to be particularly useful for modeling biomolecular systems5 as well as for transition metal complexes and catalysts.6

Codes that support ONIOM

See also

See also

External links
References

References

  1. "Investigating the Reactivity and Spectra of Large Molecules with ONIOM | Gaussian.com". gaussian.com. Retrieved 2023-04-13.
  2. S. Dapprich; I. Komaromi; K.S. Byun; K. Morokuma & M.J. Frisch (1999). "A new ONIOM implementation in Gaussian98. Part I. The calculation of energies, gradients, vibrational frequencies and electric field derivatives". Journal of Molecular Structure: THEOCHEM. 461–462: 1–21. doi:10.1016/S0166-1280(98)00475-8.
  3. Vreven, T; Morokuma, K (2006). "Chapter 3 Hybrid Methods: ONIOM(QM:MM) and QM/MM". Annual Reports in Computational Chemistry. 2: 35–51. doi:10.1016/S1574-1400(06)02003-2. ISBN 9780444528223.
  4. Svensson, Mats; Humbel, StéPhane; Froese, Robert D. J.; Matsubara, Toshiaki; Sieber, Stefan; Morokuma, Keiji (1996). "ONIOM: A Multilayered Integrated MO + MM Method for Geometry Optimizations and Single Point Energy Predictions. A Test for Diels−Alder Reactions and Pt(P(t-Bu)3)2+ H2Oxidative Addition". The Journal of Physical Chemistry. 100 (50): 19357. doi:10.1021/jp962071j.
  5. Senn, H; Thiel, W (2007). "QM/MM studies of enzymes". Current Opinion in Chemical Biology. 11 (2): 182–7. doi:10.1016/j.cbpa.2007.01.684. PMID 17307018.
  6. Ananikov, Valentine P.; Musaev, Djamaladdin G.; Morokuma, Keiji (2010). "Real size of ligands, reactants and catalysts: Studies of structure, reactivity and selectivity by ONIOM and other hybrid computational approaches☆". Journal of Molecular Catalysis A: Chemical. 324 (1–2): 104–119. doi:10.1016/j.molcata.2010.03.015.