Combining Density Functional Theory and Green's Function Theory: Range-Separated, Nonlocal, Dynamic, and...

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Density functional theory (DFT) approximations often struggle with electron-electron interactions.
• Accurate modeling of electron correlation is crucial for predicting molecular properties.

Purpose of the Study:

• To develop a rigorous framework combining Green's function theory and DFT.
• To create a hybrid functional that accurately describes short- and long-range electron interactions.
• To mitigate self-interaction errors in electronic structure calculations.

Main Methods:

• Combining single-particle Green's function theory with DFT.
• Separating electron-electron interactions into short- and long-range components.
• Developing the range-separated hybrid functional srSVWN5-lrGF2.

Main Results:

• The new functional is weakly basis-set dependent.
• It provides an improved description of short-range dynamic correlation.
• The many-body contribution reduces self-interaction error and enhances molecular property prediction.

Conclusions:

• The hybrid framework offers a more accurate description of electronic structure.
• The functional mitigates self-interaction errors inherent in DFT.
• Potential for efficient calculations on large molecules and periodic systems is demonstrated.