Benchmark-Quality Semiexperimental Structural Parameters of van der Waals Complexes

Accurate
data sets including noncovalent interactions have become
essential for benchmarking computational methods. However, while there
is much focus on obtaining an accurate description of relative energies,
reliable prediction of accurate equilibrium geometries is also important.
To facilitate the benchmarking of computed geometries, the current
work includes an accurate data set of semiexperimental equilibrium
geometries of noncovalent complexes that can be directly compared
to ab initio data. The structures are based on high-accuracy spectroscopic
data, combined with vibrational corrections at the double-hybrid density
functional level. The current work is designed to complement available
data sets of semiexperimental geometries of small rigid molecules
and ab initio geometries of complexes. The benchmark-quality data
comprises 16 complexes and includes dispersion interactions, hydrogen
bonding, CH/π···π interactions, and trimers.
In addition to the reference data, accurate counterpoise-corrected
geometries have been obtained up to the CCSD level, along with interaction
energies. A short overview of the performance of computational methods,
including dispersion-corrected B3LYP and B2PLYP functionals, is also
included.