Furthermore we have tested the binding free energy against relativistic DFT. We tested ZORA-DLPNO-CCSD(T 0 )/TZVPP on structures optimized at the ωB97X-D3BJ/aug-cc-pVTZ-PP level. This was tested against PBE0/QZ4P with SO-ZORA formalism and a gaussian nuclear model. This is found in Section S3.2 of the SI. IA, IT, or IP evauluated as the electronic binding energy relative to the value calculated at the ZORA-CCSD(T)/TZVPP level of theory. All methods using DKH or ZORA use an all-electron basis set while all other methods are using a pseudo-potential for I. Spinorbit coupling (SOC) stabilisation is calculated at DKH-ωB97X-D3BJ/aug-cc-pVQZ-DK level using 10 roots.