Toward Efficient GW Calculations Using Numerical Atomic Orbitals: Benchmarking and Application to Molecular Dynamics...

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Materials Science

Background:

• The GW approximation is a powerful tool for calculating electronic properties of materials.
• Traditional plane-wave basis sets can be computationally expensive for large systems.
• Numerical atomic orbitals offer a potentially more cost-effective alternative.

Purpose of the Study:

• To implement and benchmark an efficient GW approximation using numerical atomic orbitals.
• To assess the accuracy and cost-effectiveness of this approach for molecular systems.
• To investigate electron-phonon couplings in complex molecules.

Main Methods:

• Implementation of the GW approximation with numerical atomic orbitals and pseudopotentials.
• Utilized a contour deformation technique and one-shot quasiparticle energy extraction.
• Tested on G2/97 and acceptor molecule test sets, and applied to a photochromic compound using ab initio molecular dynamics.

Main Results:

• The numerical atomic orbital-based GW method demonstrates good performance and basis set convergence.
• Electron-phonon couplings computed with GW were found to be approximately twice as large as those from DFT-GGA.
• Frozen-phonon calculations corroborated the enhanced electron-phonon coupling findings.

Conclusions:

• The developed GW method using numerical atomic orbitals provides an efficient and accurate approach for electronic structure calculations.
• This method accurately captures electron-phonon interactions, offering insights into molecular dynamics and properties.
• The findings suggest this approach is suitable for modeling large molecules and complex phenomena.