Multireference Density Functional Theory with Generalized Auxiliary Systems for Ground and Excited States

Area of Science:

• Quantum Chemistry
• Computational Physics

Background:

• Static correlation poses a significant challenge for standard density functional theory (DFT) approximations.
• Accurate description of static correlation is crucial for understanding chemical bond breaking and molecular behavior.

Purpose of the Study:

• To develop a new DFT approach capable of describing static correlation.
• To rigorously achieve a multideterminant description of physical systems.

Main Methods:

• A generalized auxiliary system with different symmetry from the physical system is employed.
• Total energy is decomposed into auxiliary system energy (using a density functional approximation) and excitation energy from linear response theory.
• A generalized optimized effective potential method is used for self-consistent optimization.

Main Results:

• The developed multireference DFT successfully describes static correlation.
• Numerical results demonstrate accuracy in modeling bond dissociation and double bond rotation.

Conclusions:

• The novel DFT approach provides a robust framework for treating static correlation.
• This method offers a promising avenue for accurate quantum chemical calculations.