Assessing the Limitations of Self-Interaction-Corrected Functionals for Describing the Hydrated Electron.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Theoretical chemistry

Background:

• Standard density functional theory (DFT) functionals struggle with self-interaction error when simulating the hydrated electron.
• Hybrid functionals like PBEh(40) improve accuracy but are computationally expensive for large simulations.
• Explicit self-interaction correction (SIC) schemes offer a potential computationally efficient alternative.

Purpose of the Study:

• To evaluate the Perdew-Zunger self-interaction correction (PZ-SIC) scheme applied to the revPBE functional as a computationally efficient alternative to PBEh(40) for the hydrated electron.
• To assess the physical sensibility and accuracy of PZ-SIC for hydrated electron simulations.

Main Methods:

• Density functional theory (DFT) calculations.
• Application of the Perdew-Zunger self-interaction correction (PZ-SIC) scheme.
• Comparison with hybrid functionals (PBEh(40)) and generalized gradient approximation (GGA) functionals.
• Analysis of the hydrated electron and its reactivity.

Main Results:

• Functionals with self-interaction correction (SIC) should be used with caution for the hydrated electron and its reactivity.
• The PZ-SIC scheme applied to revPBE did not prove to be a universally reliable or efficient alternative to PBEh(40).
• Extensive sampling and diverse chemical environments are crucial for validating DFT functional performance.

Conclusions:

• Explicit self-interaction correction schemes require careful consideration and validation for simulating the hydrated electron.
• The computational efficiency of SIC methods does not guarantee physical accuracy for this challenging system.
• Future work should focus on developing robust and accurate DFT methods for solvated electrons, emphasizing thorough validation protocols.