Fast, efficient, and accurate dielectric screening using a local real-space approach.

Area of Science:

• Computational physics
• Quantum chemistry
• Materials science

Background:

• Many-body perturbation theory relies on the screened Coulomb interaction (W) for electron behavior calculations.
• Accurate dielectric response is crucial for predicting electronic and structural properties.
• Current methods like the random-phase approximation (RPA) are computationally expensive, scaling as N^4.

Purpose of the Study:

• To extend an efficient local approach, previously successful for core-level excitations, to valence-level excitations.
• To improve the accuracy and computational efficiency of calculating the screened Coulomb interaction (W).
• To enable more reliable predictions of electronic and structural properties in materials.

Main Methods:

• Extension of a local screening approach to valence electronic systems.
• Reconstruction of all-electron wave function character from pseudopotential calculations.
• Implementation of improved computational scaling (N^2 log N) and parallelization.

Main Results:

• Demonstrated improved accuracy and execution efficiency for the local screening method.
• Achieved better than N^4 scaling, approaching N^2 log N, for computational cost.
• Successfully applied the method to Bethe-Salpeter equation calculations for spectroscopies.

Conclusions:

• The enhanced local approach offers a more efficient and accurate alternative to traditional methods for computing W.
• This method significantly reduces computational cost, making complex calculations more feasible.
• The approach is applicable to both core and valence spectroscopies, broadening its utility.