Describing a Strongly Correlated Model System with Density Functional Theory.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Hydrogen chains serve as a fundamental model for metal-to-Mott insulator transitions.
• Understanding strong correlation is crucial for materials science.

Purpose of the Study:

• To investigate the electronic structure and phase transitions in linear hydrogen chains.
• To apply a new density functional theory (DFT) model for strongly correlated systems.
• To explore the Peierls dimerization in a Mott insulating hydrogen chain.

Main Methods:

• Utilized a recent DFT model functional designed for nondynamic and strong correlation.
• Computed the cohesive energy curve for the metal-insulator transition.
• Developed a DFT descriptor to quantify localized electrons.
• Analyzed the Peierls dimerization in a Mott insulator.

Main Results:

• The computed cohesive energy curve accurately matches literature data.
• A novel DFT descriptor effectively characterizes electronic structure variations.
• The study successfully depicts phase transitions in a semiquantitative phase diagram.
• Demonstrated the feasibility of studying strongly correlated materials with mean-field DFT.

Conclusions:

• The DFT model accurately captures the transition from metallic to Mott insulating states in hydrogen chains.
• The developed descriptor provides insights into electron localization.
• Mean-field DFT models can effectively study strongly correlated materials, challenging prior pessimism.