Comparison of Density-Matrix Corrections to Density Functional Theory.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Density functional theory (DFT) is a widely used computational chemistry method.
• DFT fails to accurately describe systems with statically correlated electrons.
• Existing methods require improvement for complex electronic systems.

Purpose of the Study:

• To address the limitations of DFT in describing statically correlated electrons.
• To investigate the performance of a one-electron reduced density matrix theory (1-RDMFT) approach.
• To generalize and compare information density matrix functional theory (iDMFT) with the 1-RDMFT method.

Main Methods:

• Transforming DFT into 1-RDMFT using a quadratic 1-RDM correction.
• Combining 1-RDMFT with various DFT functionals and Hartree-Fock.
• Generalizing iDMFT by incorporating density functionals.
• Benchmarking 1-RDMFT and iDMFT with common functionals and systems.

Main Results:

• The study elucidates the dependence of the 1-RDMFT approach on the chosen DFT functional.
• The generalized iDMFT incorporates density functionals, extending its applicability.
• Mathematical relationships between 1-RDMFT and iDMFT are established.
• Comparative benchmarking provides insights into the performance of both methods.

Conclusions:

• The developed 1-RDMFT offers a promising alternative for systems with static electron correlation.
• Generalizing iDMFT enhances its utility in computational chemistry.
• The study provides a foundation for further development and application of these advanced quantum chemical methods.