ONIOM

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.^[2][3][4]

The ONIOM computational approach has been found to be particularly useful for modeling biomolecular systems^[5] as well as for transition metal complexes and catalysts.^[6]

Codes that support ONIOM

• Gaussian
• NWChem
• ORCA (quantum chemistry program)

See also

• QM/MM
• Steric effects (ONIOM to separate Steric effects vs. electronic effects)

External links

• Morokuma Group Home Page