Local self-interaction correction method with a simple scaling factor.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Standard Perdew-Zunger SIC (PZSIC) has limitations in accurately predicting electronic properties.
• A recently proposed local self-interaction correction (LSIC) method shows promise for improving PZSIC.
• LSIC utilizes an iso-orbital indicator to identify single-electron regions for correction.

Purpose of the Study:

• To explore a simpler scaling factor for the LSIC method using a ratio of orbital and spin densities.
• To evaluate the performance of LSIC with this new scaling factor against PZSIC and LSIC(zσ).
• To assess the accuracy of different LSIC scaling factors for equilibrium and non-equilibrium properties, including water clusters.

Main Methods:

• Implementation of LSIC with a density ratio scaling factor.
• Computation of equilibrium properties (e.g., total energies, atomization energies).
• Computation of non-equilibrium properties (e.g., barrier heights) and binding energies of water clusters.

Main Results:

• LSIC with the density ratio scaling factor outperforms PZSIC for most properties.
• Results using the density ratio scaling factor are comparable to LSIC(zσ), with slightly larger errors.
• LSIC(zσ) struggles with water cluster binding energies, while the density ratio scaling factor performs well.

Conclusions:

• LSIC with a density ratio scaling factor offers a viable and simpler alternative to LSIC(zσ).
• The choice of iso-orbital indicator and scaling factor is crucial for accurate electronic structure calculations.
• This work highlights the importance of selecting appropriate scaling factors for LSIC in different chemical systems.