Multi-Basis-Set (TD-)DFT Methods for Predicting Electron Attachment Energies.

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Quantum Chemistry

Background:

• Low-energy electron collisions with molecules can form temporary anions through resonant processes.
• Experimental techniques like electron transmission spectroscopy are effective but simulating electron attachment remains difficult.

Purpose of the Study:

• To develop and validate a computational methodology for calculating electron attachment resonance energies.
• To provide a reliable theoretical approach for studying temporary anions.

Main Methods:

• Utilizing ab initio (time-dependent) density functional theory (TD-DFT) calculations.
• Employing two distinct basis sets: a large one with diffuse functions for vertical electron affinity and a smaller one for anion excitation energy.
• Calculating 53 resonance energies for 18 different molecules.

Main Results:

• The proposed computational method demonstrates high reliability in predicting resonance energies.
• Calculated values show good agreement with existing experimental data.

Conclusions:

• The developed TD-DFT methodology offers an accurate and efficient approach for simulating electron attachment processes.
• This method can aid in the characterization of temporary anions in molecular systems.