A Restriction-Based Configuration Interaction Approach Based on LC-DFTB: An Efficient Method for Field-Induced Charge...

Area of Science:

• Computational chemistry
• Molecular electronics
• Materials science

Background:

• Electron transfer is key in molecular electronics, but traditional methods struggle with one-electron transfer under electric fields.
• Accurate modeling is needed for molecular wires, switches, and organic photovoltaics.

Purpose of the Study:

• To develop a novel computational method for accurate electron transfer description under external electric fields.
• To extend long-range corrected self-consistent-charge density functional tight binding (LC-DFTB) for improved accuracy in molecular electronics.

Main Methods:

• Introduced restriction-based configuration interaction (RCI) LC-DFTB, combining LC-DFTB with configuration interaction principles.
• Retained the computational efficiency of LC-DFTB while enhancing its ability to describe charge-resonance and field-induced responses.
• Applied the method to a benzene assembly and a polyfluorene system.

Main Results:

• RCI-LC-DFTB accurately captures one-electron transfer phenomena under external electric fields.
• The method efficiently describes the influence of molecular conformation and applied bias on electron localization and transfer.
• Demonstrated robust performance on complex molecular systems.

Conclusions:

• RCI-LC-DFTB offers a powerful and cost-effective tool for studying electron transfer in molecular systems.
• This method facilitates the rational design of advanced molecular electronic and organic photovoltaic materials.