Reproducibility in density functional theory calculations of solids

Area of Science:

• Solid-state physics
• Computational materials science
• Quantum chemistry

Background:

• Density functional theory (DFT) is widely used for predicting material properties.
• Numerous DFT codes exist, but variations in implementation raise reproducibility concerns.
• Standardized benchmarking is needed to assess code accuracy and reliability.

Purpose of the Study:

• To evaluate the reproducibility and accuracy of DFT codes for crystalline solids.
• To compare the performance of 15 solid-state DFT codes using various potentials and basis sets.
• To assess the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional for elemental crystals.

Main Methods:

• Community-wide benchmarking effort involving 15 solid-state DFT codes.
• Utilized 40 different pseudopotential and basis set combinations.
• Calculated equations of state for 71 elemental crystals using the PBE functional.

Main Results:

• Recent DFT codes and pseudopotentials demonstrate high agreement for crystal properties.
• Pairwise differences between modern codes are comparable to experimental uncertainties.
• Older DFT methods show significantly less precise agreement.
• The study established a benchmark for assessing PBE predictions.

Conclusions:

• Modern DFT codes offer reliable and reproducible predictions for crystalline solids.
• The developed benchmark framework aids in evaluating new DFT methods and improvements.
• Users and developers can leverage this work to ensure prediction quality and consistency.