Calculation of divergenceless magnetically induced current density in molecules.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Molecular Modeling

Background:

• Accurate calculation of magnetically induced quantum mechanical current densities is crucial for understanding molecular properties.
• Conventional current density calculations often exhibit non-zero divergence, violating the continuity requirement.

Purpose of the Study:

• To present a novel method for calculating divergenceless, magnetically induced quantum mechanical current densities.
• To improve the continuity and physical realism of calculated current densities in molecules.

Main Methods:

• The method adds a corrective term to the conventional current density, derived from the irrotational part of its Helmholtz decomposition.
• The resulting solenoidal field represents a divergence-free approximation of the exact current density.
• Calculations were performed on small molecules (LiH, H2O, benzene, zethrene) using various theoretical approaches.

Main Results:

• The proposed method yields current densities that satisfy the continuity requirement, irrespective of basis set quality.
• Observed improvements in the correspondence of vortices, sources, and sinks compared to conventional methods.
• A minor improvement in the calculated diagonal components of the magnetizability tensor was noted.

Conclusions:

• The developed method provides a more physically realistic and accurate representation of quantum mechanical current densities.
• This approach enhances the reliability of molecular modeling and the interpretation of magnetic properties.
• The technique offers a valuable tool for computational chemists studying electron dynamics in molecules.