Benchmarking experiments for numerical quantum chemistry

The relationship between experiment and quantum chemistry can adopt puzzle solving or benchmarking character, depending on whether theory assists in the interpretation of experiment or experiment is used to judge the performance of different quantum chemical approaches. For the spectroscopy of non-covalent interactions, both directions are very useful, but benchmarking activities increasingly tend to avoid experiment and to focus on theory-internal rankings of electronic energy performance. This is understandable in view of obstacles such as quantum dynamics, thermal motion, or environment and in view of the relative maturity of electronic structure theory, but it cannot be fully satisfactory. ^[1] Heilbronner and Hückel always had an eye for experiment and as experimentalists we should do our best to remove such obstacles, to enable conclusive experimental benchmarking.  The talk will address some strategies for fruitful relationships between experimental vibrational spectroscopy and electronic structure theory, including the folding of alkanes and the concept of intermolecular energy balances. ^[2]

[1] R.A. Mata and M.A. Suhm, Benchmarking quantum chemical methods: are we heading in the right direction?, Angew. Chem. Int. Ed. 56 (2017) 11011–11018

[2] A. Poblotzki, H.C. Gottschalk, M.A. Suhm, Tipping the Scales: Spectroscopic Tools for Intermolecular Energy Balances, J. Phys. Chem. Lett. 8 (2017) 5656–5665