Benchmark-Quality Semiexperimental Structural Parameters of van der Waals Complexes

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Molecular Modeling

Background:

• Accurate computational methods require reliable data sets for benchmarking.
• Focus on relative energies often overshadows the importance of accurate equilibrium geometries.

Purpose of the Study:

• To create a benchmark-quality data set of semiexperimental equilibrium geometries for noncovalent complexes.
• To facilitate the direct comparison of computed geometries with high-accuracy experimental data.

Main Methods:

• Utilizing high-accuracy spectroscopic data.
• Incorporating vibrational corrections at the double-hybrid density functional level.
• Obtaining counterpoise-corrected geometries up to the Coupled Cluster Singles Doubles (CCSD) level.

Main Results:

• A data set of 16 noncovalent complexes with benchmark-quality semiexperimental equilibrium geometries.
• Inclusion of various interactions: dispersion, hydrogen bonding, and CH/π···π interactions.
• Analysis of computational method performance, including dispersion-corrected functionals.

Conclusions:

• The developed data set complements existing resources for computational chemistry benchmarking.
• Accurate equilibrium geometries are vital for validating computational models of noncovalent interactions.