Semiempirical Quantum-Chemical Orthogonalization-Corrected Methods: Benchmarks for Ground-State Properties

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Standard semiempirical methods like MNDO have limitations in accuracy.
• Accurate treatment of noncovalent interactions is crucial in chemistry.
• The OMx methods (OM1, OM2, OM3) were developed to improve upon standard models.

Purpose of the Study:

• To evaluate the performance of OMx and OMx-Dn methods for ground-state properties.
• To compare OMx and OMx-Dn against established semiempirical methods.
• To assess the accuracy of empirical dispersion corrections for noncovalent interactions.

Main Methods:

• Utilized OMx (OM1, OM2, OM3) and OMx-Dn methods.
• Employed a large benchmark dataset (13035 data points).
• Compared results with MNDO, AM1, PM3, PM6, and PM7 methods.

Main Results:

• OMx and OMx-Dn methods demonstrated superior performance across most benchmark sets.
• Empirical dispersion corrections (Dn) enhanced the treatment of noncovalent interactions.
• OMx methods showed improved accuracy over standard NDDO-based methods.

Conclusions:

• OMx and OMx-Dn represent robust and accurate semiempirical approaches.
• These methods provide a valuable tool for electronic structure calculations.
• The study validates the effectiveness of OMx methods for diverse chemical properties.