Simple DFT Scheme for Estimating Negative Electron Affinities.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Theoretical Chemistry

Background:

• Estimating electron affinities is crucial in chemistry.
• Existing density functional theory (DFT) methods have limitations in accuracy.
• Accurate calculations of electron affinities require careful treatment of electron interactions.

Purpose of the Study:

• To develop a simple and accurate DFT scheme for estimating negative vertical electron affinities.
• To address the integer discontinuity and density scaling homogeneity in DFT.
• To improve upon existing DFT methods for electron affinity calculations.

Main Methods:

• Proposed a novel DFT scheme utilizing two system-dependent exchange-correlation functionals.
• Calculated electron affinities as a linear combination of frontier orbital energies.
• Employed self-consistent Kohn-Sham calculations on neutral systems.

Main Results:

• The proposed scheme accurately estimates electron affinities for 43 molecules.
• Results show good agreement with experimental values.
• The method outperforms the Tozer and De Proft DFT approach.

Conclusions:

• The developed DFT scheme offers a simple and effective way to calculate electron affinities.
• The method is computationally inexpensive and easy to implement.
• Provides a practical approach for obtaining accurate frontier orbital energies without exact exchange.