DC24: A new density coherence functional for multiconfiguration density-coherence functional theory.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Theoretical chemistry

Background:

• Density coherence (DC) functionals are crucial for accurate modeling in multiconfiguration density-coherence functional theory.
• Previous DC functionals have limitations in accuracy and physical interpretation.

Purpose of the Study:

• To explore and develop novel functional forms for DC functionals.
• To enhance the accuracy and physical interpretability of DC functionals.
• To introduce a new definition for unpaired electron density.

Main Methods:

• Systematic exploration of alternative functional forms for DC functionals.
• Parameterization of each functional against a consistent database.
• Evaluation of functional performance based on mean unsigned error.

Main Results:

• The development of a new, highly accurate DC functional named DC24.
• DC24 demonstrates a mean unsigned error of 1.73 kcal/mol, a 9% improvement over previous functionals.
• DC24 exhibits a more physically meaningful interpretation.

Conclusions:

• The new DC24 functional represents a significant advancement in multiconfiguration density-coherence functional theory.
• The improved accuracy and physical interpretation of DC24 will benefit computational chemistry.
• The novel definition of unpaired electron density may have broader applications.