A simple model for calculating atomic charges in molecules.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Materials Science

Background:

• Accurate atomic charge calculation is crucial for understanding molecular properties and reactivity.
• Existing atomic charge analysis methods have limitations in accuracy, consistency, and basis set dependency.

Purpose of the Study:

• To develop and validate a novel atomic charge analysis method, the adjusted charge partitioning (ACP) scheme.
• To assess the performance of the ACP scheme against established methods using a diverse set of molecules.

Main Methods:

• The adjusted charge partitioning (ACP) scheme utilizes weighting factors cAr^(2n-2)exp(-αAr) with atomic parameters cA and αA.
• Extensive numerical tests were conducted on 540 molecules across 17 main-group elements.
• Atomic charges and dipole moments were compared with results from Mulliken, Löwdin, Hirshfeld, CM5, ESP, NPA, and QTAIM methods.

Main Results:

• The ACP scheme demonstrates insensitivity to the choice of basis sets used in calculations.
• Generated atomic charges are chemically consistent and reliable.
• The method accurately reproduces experimental dipole moments for the tested molecules.

Conclusions:

• The adjusted charge partitioning (ACP) scheme offers a robust and accurate approach for atomic charge analysis.
• ACP provides a valuable alternative to existing methods, particularly for its basis set independence and chemical consistency.
• This method enhances the predictive power of computational chemistry for molecular properties.