An unexpected bridge between chemical bonding indicators and electrical conductivity through the localization tensor

Area of Science:

• Quantum Chemistry
• Materials Science
• Condensed Matter Physics

Background:

• The localization tensor (LT) is a key theoretical tool for determining a system's conducting or insulating properties from its ground state.
• A chemical interpretation of the LT has been lacking, hindering its application in traditional chemical analysis.

Purpose of the Study:

• To establish a direct chemical interpretation of the localization tensor (LT).
• To link the LT to established chemical bonding concepts, specifically delocalization indices (DIs).
• To enable the use of chemical intuition for predicting electrical conductivity.

Main Methods:

• Real-space partitioning of the LT into intra- and interatomic contributions.
• Analysis of the relationship between LT behavior and delocalization indices (DIs).
• Investigating the thermodynamic limit of the LT and its dependence on DI spatial decay rates.

Main Results:

• A direct correlation between the LT and delocalization indices (DIs) was established.
• The insulating or conducting nature of extended systems was shown to be determined by the convergence or divergence of the LT, respectively.
• The spatial decay rate of interatomic DIs (exponential for insulators, power-law for conductors) dictates the thermodynamic limit of the LT.

Conclusions:

• The study provides the first chemical reading of the localization tensor.
• Delocalization indices offer a powerful tool for understanding and predicting electrical conductivity based on chemical bonding.
• This work bridges quantum mechanical theory with chemical intuition for materials properties.