All quantum chemical calculations were done using density functional theory (DFT) and were performed using the program ORCA 5.0.4. The geometry optimisations and dissociation scans of the water dimer have been performed using every permutation of the Ahlrich basis sets 39 def2-SVP, def2-TZVP and def2-QZVPP and the functionals BP86, 40 B3LYP 41 and wB97X. For each combination of density functional and basis set, calculations with and without implicit solvation (CPCM) and D3 corrections were conducted. We chose a stepsize of 0.05Å for scanning the bond dissociation. Some dissociation scans required several geometry constrains (as indicated for each species). For sake of comparability with previous studies, we performed all geometry optimisations for C 2 F 4 with M06L, where all single-point calculations were performed using M08HX 45 with the Dunning basis set aug-cc-pVTZ. The Pd and the Au complexes were optimised using the def2-SVP basis set and the B3LYP functional. All frequency calculations have been calculated with the same combina-tion of settings as the corresponding optimised geometries. Quantum chemical descriptors, such as Mulliken partial charges, bond order indices, we calculated using the wave-function analysis tool Multiwfn. All of the fitting functions have been computed using the leastquares algorithm of Python 3 package SciPy and are available as a Jupyter-Notebook (). An example output plot can be found in the Supporting Information, Figure .