Counterpoise corrections were applied to PBE0+MBD and CCSD(T) single-point calculations. The basis set superposition error was negligibly small (under 1.5%) for the former and ca. 4% on the average for the latter in the complete basis set (CBS) limit (see results in Fig. of the SI). To investigate the level of agreement among QM methods for calculating E int of QUID dimers, we have considered a selection of well-performing DFT functionals, including M06-2X , ωB97X-D3 21 , ωB97M-V . Additionally, the PBE0 functional was combined with multiple two-body or many-body corrections: MBD (range-separated self-consistent screening (MBD@rsSCS) approach), MBD-NL (Non-Local), XDM (eXchange Dipole Moment), TS (Tkatchenko-Scheffler)-vdW , D4 , ωB97X-D3 21 , ωB97M-V 60 . These calculations were performed using either the FHI-Aims (version 221103 )software with "tight" settings or the Psi4 software (version 1.9.1) with the quadruple-zeta def2-QZVPPD basis set. Notably, for the XDM method, a specific parametrization for the PBE0 functional was applied and then computed using FHI-aims software on "tight" settings (a 1 =0.4710 and a 2 =2.3857) . SAPT energy decomposition calculations were carried out at the sSAPT0/jaDZ level employing the Psi4 software 75 (version 1.9.1). At the semiempirical level, E int was calculated via single-point calculations using Density Functional Tight Binding 15 DFTB3+MBD