CHAL336 Benchmark Set: How Well Do Quantum-Chemical Methods Describe Chalcogen-Bonding Interactions?

We
present the CHAL336 benchmark setthe most comprehensive
database for the assessment of chalcogen-bonding (CB) interactions.
After careful selection of suitable systems and identification of
three high-level reference methods, the set comprises 336 dimers each
consisting of up to 49 atoms and covers both σ- and π-hole
interactions across four categories: chalcogen–chalcogen, chalcogen−π,
chalcogen–halogen, and chalcogen–nitrogen interactions.
In a subsequent study of DFT methods, we re-emphasize the need for
using proper London dispersion corrections when treating noncovalent
interactions. We also point out that the deterioration of results
and systematic overestimation of interaction energies for some dispersion-corrected
DFT methods does not hint at problems with the chosen dispersion correction
but is a consequence of large density-driven errors. We conclude this
work by performing the most detailed DFT benchmark study for CB interactions
to date. We assess 109 variations of dispersion-corrected and dispersion-uncorrected
DFT methods and carry out a detailed analysis of 80 of them. Double-hybrid
functionals are the most reliable approaches for CB interactions,
and they should be used whenever computationally feasible. The best
three double hybrids are SOS0-PBE0-2-D3­(BJ), revDSD-PBEP86-D3­(BJ),
and B2NCPLYP-D3­(BJ). The best hybrids in this study are ωB97M-V,
PW6B95-D3(0), and PW6B95-D3­(BJ). We do not recommend using the popular
B3LYP functional nor the MP2 approach, which have both been frequently
used to describe CB interactions in the past. We hope to inspire a
change in computational protocols surrounding CB interactions that
leads away from the commonly used, popular methods to the more robust
and accurate ones recommended herein. We would also like to encourage
method developers to use our set for the investigation and reduction
of density-driven errors in new density functional approximations.