Self-consistent-field (SCF) steps in this work were carried out with energy convergence criteria of 10 -7 E h (TURBOMOLE) and 10 -8 E h (ORCA). The frozen-core approximation was applied across all TURBOMOLE calculations, and in ORCA 147,148 calculations it was used along with the RI approximation for the perturbative parts of the double hybrids. Large quadrature-grid options "7" (TURBOMOLE) and "grid6 finalgrid7" (ORCA) were used to ensure smooth dissociation curves. Dispersion corrections of the type DFT-D3(BJ) DFT-D4 122,123 were carried out with the DFTD3 and DFTD4 standalone programs. Damping parameters for the various functionals were taken from the respective reference that published them first. A series of different basis sets-ranging from double-ζ (DZ) to quadruple-ζ (QZ)-were employed throughout this work, with some of them used for extrapolations to the CBS limit. More information is provided in the following sections.