Use of Gaussian-Type Functions for Describing Fast Ion-Matter Irradiation with Time-Dependent Density Functional...

Area of Science:

• Computational Physics
• Quantum Chemistry
• Materials Science

Background:

• Electronic stopping power quantifies energy transfer from swift ions to matter's electron cloud.
• Real-Time Time-Dependent Density Functional Theory (RT-TDDFT) is valuable for first-principles calculations.
• Limitations exist in atom-centered basis functions for capturing ion-matter interaction physics.

Purpose of the Study:

• To investigate the impact of continuum wave function-mimicking Gaussian atomic orbitals (AOC) on electronic stopping power predictions.
• To address the challenge of accurately modeling electron emission during ion irradiation.
• To enhance the predictive capability of computational codes for ion-matter interactions.

Main Methods:

• Incorporation of adapted Gaussian atomic orbitals (AOC) into standard basis sets (correlation-consistent or STO minimal).
• Benchmarking calculations for water irradiated by fast protons.
• Focusing AOC placement on impacted molecules.

Main Results:

• AOC significantly improve electronic stopping power predictions, particularly near the Bragg peak.
• The addition of AOC enhances the capture of electron emission physics.
• Optimized basis sets show encouraging agreement with experimental data for proton stopping power in water.

Conclusions:

• Adapted Gaussian atomic orbitals (AOC) are effective for improving electronic stopping power calculations.
• AOC offer a computationally efficient method to enhance accuracy in ion-matter interaction simulations.
• This approach provides a more robust framework for predicting ion penetration and energy transfer in materials.