Density-Based Basis-Set Incompleteness Correction for GW Methods.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Many-body perturbation theory (MBPT) methods like GW approximation face slow convergence in energetic properties.
• This convergence issue stems from the absence of explicit electron-electron terms accounting for the Kato cusp and correlation Coulomb hole.

Purpose of the Study:

• To introduce a computationally efficient, density-based basis-set correction method.
• To accelerate the convergence of energetic properties towards the complete basis set limit in GW calculations.

Main Methods:

• Proposed a density-based correction utilizing short-range correlation density functionals.
• Applied the correction to calculate ionization potentials using the perturbative GW (G0W0) level.
• Tested the method on the GW100 set (20 smallest atoms/molecules) and five canonical nucleobases.

Main Results:

• The density-based correction significantly speeds up the convergence of energetics.
• Accurate ionization potentials were obtained for atoms, molecules, and nucleobases.
• Demonstrated substantial improvement in GW calculations with the new correction method.

Conclusions:

• The proposed density-based correction is an efficient approach to mitigate basis set convergence issues in GW calculations.
• This method enhances the accuracy of ionization potential predictions for various chemical systems.
• Offers a promising avenue for more reliable and efficient electronic structure calculations.