Requirements for an accurate dispersion-corrected density functional

Post-self-consistent dispersion corrections are now the norm when applying density-functional theory to systems where non-covalent interactions play an important role. However, there is a wide range of base functionals and dispersion corrections available from which to choose. In this work, we opine on the most desirable requirements to ensure that both the base functional and dispersion correction, individually, are as accurate as possible for non-bonded repulsion and dispersion attraction. The base functional should be dispersionless, numerically stable, and involve minimal delocalization error. Simultaneously, the dispersion correction should include finite damping, higher-order pairwise dispersion terms, and electronic many-body effects. These criteria are essential for avoiding reliance on error cancellation and obtaining correct results from correct physics.

Automated summary

In this study, the authors discuss the optimal requirements for the base functional and dispersion correction to accurately account for non-bonded repulsion and dispersion attraction. They emphasize the importance of having a dispersionless, numerically stable base functional with minimal delocalization error, as well as a dispersion correction that includes finite damping, higher-order pairwise dispersion terms, and electronic many-body effects. These criteria are crucial for avoiding error cancellation and obtaining correct results based on accurate physics principles.