[Perspective] A benchmark for materials simulation
Density functional theory (DFT) stands out from all first-principles quantum mechanical methods for the simulation of materials, as it enables very good approximations for the complicated components of electronic motion called exchange and correlation. DFT is the method of choice for many materials simulations because of the availability of general-purpose programs that can perform calculations on any material. Results obtained with one DFT program need to be reproducible by any of the other DFT programs, and this has not been straightforward up to now. On page 10.1126/science.aad3000 of this issue, Lejaeghere et al. (1) describe an extensive effort by developers of the major solid-state DFT codes to provide a unified and reproducible benchmark of precision for their calculations based on a reliable criterion, the so-called Δ gauge. Using the Δ gauge, the authors found that the level of precision that can be achieved today in DFT calculations of elemental crystalline...