Comparison of direct and flow integration based charge density population analyses.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Molecular Modeling

Background:

• Accurate calculation of atomic charges (Q(A)) is crucial for understanding molecular properties.
• Existing methods for partitioning molecular electron density (rho) into atomic densities (rho(A)) have limitations.

Purpose of the Study:

• To compare different methods for computing atomic charges (Q(A)) from molecular electron density (rho).
• To evaluate the reliability and basis set dependence of atomic charge calculation methods.

Main Methods:

• Employed exhaustive and fuzzy partitioning of molecular electron density (rho).
• Calculated atomic charges (Q(A)) via direct integration of atomic densities (rho(A)).
• Compared results with charges derived from integrating deformation density (rho(def)).

Main Results:

• Atomic charges derived from deformation density integration resemble reference atomic densities.
• Basis set independence of charges is linked to insensitivity of atomic domains, not intrinsic quality.

Conclusions:

• Methods integrating deformation density may not yield intrinsically superior atomic charges.
• The choice of atomic domains significantly influences basis set independence of calculated charges.