Finite Difference Interpolation for Reduction of Grid-Related Errors in Real-Space Pseudopotential Density Functional...

Area of Science:

• Computational physics
• Materials science
• Quantum chemistry

Background:

• Real-space pseudopotential methods are crucial for large-scale density functional theory (DFT) calculations.
• A significant limitation is the "egg-box" effect, caused by grid positioning errors, which can be mitigated by finer grids, increasing computational cost.
• Reducing the "egg-box" effect for a given grid resolution is an active area of research.

Purpose of the Study:

• To present a novel finite difference interpolation method for electron orbitals.
• To systematically reduce "egg-box" effects in real-space pseudopotential DFT calculations.
• To improve the accuracy and efficiency of large-scale electronic structure calculations.

Main Methods:

• Implementation of a finite difference interpolation technique for electron orbitals.
• Application of the method within the PARSEC code, a finite difference real-space pseudopotential DFT program.
• Systematic analysis of "egg-box" error reduction and convergence improvement.

Main Results:

• Demonstrated successful mitigation of "egg-box" errors using the proposed interpolation method.
• Achieved improved convergence in DFT calculations with minimal additional computational expense.
• Validated the effectiveness of the method in reducing grid-related inaccuracies.

Conclusions:

• Finite difference interpolation of electron orbitals offers an effective strategy to combat "egg-box" effects in real-space DFT.
• The method provides a favorable balance between accuracy improvement and computational cost.
• This technique enhances the feasibility and reliability of large-scale electronic structure simulations.