Polarizability of Polymers Using One-Electron Self-Interaction-Corrected Density Functional Methods.

Area of Science:

• Computational chemistry
• Materials science
• Quantum mechanics

Background:

• Density functional approximations (DFAs) commonly exhibit delocalization errors.
• These errors lead to overestimation of static linear polarizability in conjugated polymers under electric fields.
• Accurate polarizability is crucial for understanding polymer response to external stimuli.

Purpose of the Study:

• To evaluate the performance of self-interaction correction methods in predicting polymer polarizability.
• To compare Perdew-Zunger self-interaction correction (PZSIC) and locally scaled self-interaction correction (LSIC) against benchmark data.
• To identify accurate computational methods for conjugated polymer polarization.

Main Methods:

• Application of PZSIC and LSIC methods to polydiacetylene (PDA) and polybutatriene (PBT) oligomers.
• Calculation of static linear polarizability using these methods.
• Comparison of results with benchmark coupled cluster calculations (CCSD(T)-F12).

Main Results:

• PZSIC significantly underestimates polarizability due to overbinding of electrons.
• LSIC provides an accurate description of polarization effects in PDA and PBT oligomers.
• LSIC shows one of the lowest percent errors for PBT and the lowest for PDA compared to literature methods.

Conclusions:

• LSIC is a promising method for accurately calculating the static linear polarizability of conjugated polymers.
• Self-interaction correction is essential for mitigating delocalization errors in DFAs.
• LSIC offers a reliable approach for studying electronic properties of organic materials.