Ground state 87 Rb-coat-molecule structures were optimised at the MP2 level of theory with the def2-TZVP basis set, with an effective-core-potential (ECP) for a Rb atom, using Gaussian 16 Rev. A.03. OpenMolcas 15 was employed to perform state-averaged CASSCF and CASPT2 calculations on the lowest energy ground state structures and potential energy scans along the coordinate between 87 Rb and each coat molecule. The Sapporo TZP 2012 all-electron basis set was used for the CASSCF and CASPT2 calculations.