To get a notion of the credibility of the discussed ADC(2) reaction profiles, we performed additional test scans at the QD-NEVPT2 level of theory (single-point calculations at the ADC(2)-optimized geometries), and with the SCS-ADC(2) method (fully relaxed scans), obtaining generally very good agreement between the tested methods. In this stage we also checked the effect of the molecular orbital active space choice on the multireference calculations results. Data obtained in these additional calculations can be found in the ESI (Figs. ).