This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101025672. This work was supported by the Research Council of Norway through its Centres of Excellence scheme, project no. 262695. T.B.P acknowledges the support of the Centre for Advanced Study in Oslo, Norway, which funded and hosted the CAS research project Attosecond Quantum Dynamics Beyond the Born-Oppenheimer Approximation during the academic year 2021-2022. Partial support from the National Science Foundation (grant no. 1856702) is also acknowledged.

Supplemental data for our article "A Quantum Definition of Molecular Structure". Version 1.1.0 contains data for additional k-medoids runs performed on different subsets of the complete sample.