The dataset consists of Infrared photodissociation (IRPD) spectra of Cu+(H2O)(H2)n (with n ≤ 3) and its isotopologue measured on the Leipzig 5 K ring-electrode ion-trap triple mass spectrometer. Besides, it contains the Energy Decomposition Analysis (EDA), the benchmark results, the harmonic and the anharmonic VPT2 frequencies results as well as the script used to get the predicted separation factor for the adsorbed dihydrogen isotopologue. HoFe₆Al₆