A Bond-Energy/Bond-Order and Populations Relationship.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Accurate thermochemistry is crucial for understanding molecular behavior and reaction mechanisms.
• Decomposing total electronic energy into physically meaningful contributions aids chemical interpretation.
• Existing methods for energy decomposition can be computationally expensive.

Purpose of the Study:

• To introduce and validate the analytical Bond Energy from Bond Orders and Populations (BEBOP) model.
• To provide a computationally efficient method for intramolecular bond energy decomposition.
• To enable detailed chemical insight into molecular thermochemistry.

Main Methods:

• Implementation using minimum basis set Mulliken population analysis on Hartree-Fock orbitals.
• Parametrization based on atom-specific and atom pair-specific parameters.
• Fitting to reproduce CBS-QB3 thermochemistry data for accuracy.

Main Results:

• BEBOP model achieves computational cost similar to Hartree-Fock calculations with large basis sets.
• Atomization energies show comparability to widely used hybrid Density Functional Theory (DFT) methods.
• The model successfully decomposes energies into physically interpretable contributions like bond dissociation and resonance energies.

Conclusions:

• The BEBOP model offers a cost-effective approach for detailed analysis of intramolecular bond energies.
• It provides valuable chemical insights into thermochemistry and reaction mechanisms.
• The model serves as a useful tool for the computational chemistry community, complementing DFT and semiempirical methods.