System-dependent exchange-correlation functional with exact asymptotic potential and εHOMO ≈ - I

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Accurate modeling of electron behavior is crucial in quantum chemistry.
• Existing density functionals often struggle with electron-deficient systems and asymptotic potential behavior.

Purpose of the Study:

• To develop an explicit density functional addressing limitations of current models.
• To improve the description of electron-deficient systems and asymptotic exchange-correlation potentials.

Main Methods:

• Utilizing density scaling considerations to derive a novel functional.
• Employing generalized gradient approximation (GGA) calculations to determine system-dependent parameters.
• Comparing results with established GGA methods.

Main Results:

• The new functional yields exchange-correlation energies comparable to GGA.
• HOMO energies are significantly closer to ionization potentials, correctly predicting negative values for anions.
• Marked improvement in Rydberg excitation energies and near-asymptotic potential behavior.

Conclusions:

• The developed functional offers a fundamentally different and improved approach compared to conventional approximations.
• Further refinement is needed for valence excitations and non-asymptotic potential regions.
• The functional shows promise for accurate electronic structure calculations.