Construction of exchange-correlation functionals through interpolation between the non-interacting and the...

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Density functional theory (DFT) is a powerful tool for electronic structure calculations.
• Accurate exchange-correlation functionals are crucial for DFT accuracy.
• Existing functionals struggle with strongly correlated systems.

Purpose of the Study:

• To develop new exchange-correlation functionals for Kohn-Sham DFT.
• To interpolate between the non-interacting and strongly correlated limits of electron-electron interaction strength.
• To improve the accuracy of DFT calculations for various chemical and physical properties.

Main Methods:

• Utilizing the adiabatic connection formalism in DFT.
• Constructing functionals that interpolate between the exact non-interacting (exchange-only) and strong correlation limits.
• Approximating the strong correlation limit using the nonlocal-radius model.
• Developing various interpolation schemes, some empirical and some not.

Main Results:

• Proposed approximations yield exact exchange-correlation energy for one-electron systems.
• New functionals generalize global hybrids by incorporating strong correlation effects.
• Evaluated performance for molecular atomization energies, atomic energies, and ionization potentials.

Conclusions:

• The developed interpolation schemes offer improved approximations to the adiabatic connection and exchange-correlation energy.
• The new functionals show promise for accurate electronic structure calculations, particularly for challenging systems.
• This work contributes to the ongoing development of more robust and accurate DFT methods.