The molecular electronic structure revealed by the magnetically induced Lorentz force density

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Molecular Modeling

Background:

• Understanding molecular electronic structure is crucial for predicting chemical properties.
• Existing methods for analyzing magnetic responses often depend on the chosen reference point.
• Distinguishing aromaticity in molecules is a fundamental challenge in chemistry.

Purpose of the Study:

• To develop a novel, point-of-view-independent method for analyzing molecular magnetic responses.
• To establish a local definition of diamagnetic and paramagnetic responses.
• To provide a new tool for classifying molecules based on aromaticity.

Main Methods:

• Calculating the energy change in molecules under a uniform external magnetic field.
• Expressing this energy change using the magnetically induced Lorentz force density.
• Analyzing the divergence of the isotropically averaged Lorentz force density.
• Performing computational studies on model molecules like benzene, cyclooctatetraene, and borazine.

Main Results:

• The magnetically induced Lorentz force density is shown to be independent of the reference point.
• The divergence of the averaged Lorentz force density allows for local definitions of magnetic responses.
• This method successfully distinguishes between aromatic, antiaromatic, and non-aromatic molecules.
• A strong similarity was observed between the averaged Lorentz force density and the gradient of electron density.

Conclusions:

• The Lorentz force density provides a robust and versatile tool for characterizing molecular electronic structure.
• This approach offers a simplified topological characterization of molecules via their magnetic response.
• The findings open new avenues for understanding and predicting molecular behavior based on magnetic properties.