Going beyond the Computational Tool: Fermi Potential from DFT as an Electron (De)Localization Descriptor for...

Area of Science:

• Quantum Chemistry
• Materials Science
• Computational Chemistry

Background:

• Density Functional Theory (DFT) is a cornerstone of modern computational chemistry.
• Electron localization is a critical property influencing molecular and material behavior.
• Accurate descriptors for electron localization are essential for understanding chemical bonding.

Purpose of the Study:

• To highlight the utility of the Fermi potential as a descriptor for electron localization intensity.
• To demonstrate the Fermi potential's capability in characterizing bond order and nature.
• To compare the Fermi potential's accuracy against other electron localization descriptors.

Main Methods:

• Analysis of Fermi potential distribution in molecules and crystals.
• Application of Fermi potential analysis to Density Functional Theory (DFT) calculations.
• Extension of Fermi potential analysis to post-Hartree-Fock wave functions.

Main Results:

• Fermi potential wells indicate intensive electron localization, while barriers modulate electron concentration.
• The shape of Fermi potential distribution correlates with bond order in covalent bonds.
• Fermi potential components accurately capture exchange-correlation hole behavior, outperforming other descriptors.
• Analysis extends to post-Hartree-Fock methods, revealing the role of Coulomb correlation.

Conclusions:

• The Fermi potential is a robust and accurate tool for quantifying electron localization.
• It provides nuanced insights into bonding types, distinguishing covalent from noncovalent interactions.
• Its ability to preserve key features of electron correlation makes it superior to other methods for localization analysis.