Unless otherwise noted, all quantum chemical calculations were carried out using Kohn-Sham density functional theory (DFT) as implemented in the ORCA 5.0.4 quantum chemistry software package using the B3LYP exchange-correlation functional in combination with the def2-TZVP basis set and the def2/J auxiliary basis. Dispersion was treated by Grimme's D3 dispersion correction including the Becke-Johnson damping function. Acceleration of the calculations was achieved by applying resolution of identity approximation and chain of spheres exchange. To assess the nature of stationary points, the vibrational frequencies of all optimized geometries were calculated by applying the harmonic oscillator approximation. From this, we ensure the absence of imaginary frequencies for identifying minimum energy configurations on the potential energy surface.