An efficient hybrid scheme for time dependent density functional theory.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Time Dependent Density Functional Theory (TDDFT) is crucial for simulating molecular and material properties.
• Hybrid exchange-correlation (xc-) functionals offer high accuracy but are computationally expensive.
• Efficient methods are needed for accurate electronic structure calculations, especially for larger systems.

Purpose of the Study:

• To develop and validate a computationally efficient hybrid approach for TDDFT simulations.
• To introduce the Hybrid Diagonal Approximation (HDA) method.
• To demonstrate the accuracy and efficiency of HDA for various systems, including metal nanoclusters.

Main Methods:

• Implementation of the Hybrid Diagonal Approximation (HDA) scheme.
• HDA uses hybrid xc-functionals for diagonal elements and adiabatic local density approximation for off-diagonal terms in the response function.
• Testing HDA using Slater type orbital basis sets within the Amsterdam Density Functional code.

Main Results:

• HDA achieves accuracy comparable to full kernel TDDFT at a fraction of the computational cost.
• Excellent agreement was found between HDA simulations and full kernel TDDFT/experimental data for NH3, C6H6, and [Au25(SCH3)18]-.
• A speedup factor of seven was achieved for the [Au25(SCH3)18]- cluster compared to the full kernel method.

Conclusions:

• The HDA method provides a computationally affordable and accurate way to describe optical properties.
• HDA is particularly advantageous for medium-sized systems like nanoclusters.
• This approach enables quantitative optical property predictions for complex systems at reduced computational expense.