Table : Energy differences (kcal/mol) for the unsubstituted copper corrole in the S 0 and T 0 states on their optimized geometries. The values are reported at the level of theory for which geometry optimization was performed, with the exception of the RASPT2 number where the values are corrected using electronic energy contributions with RASPT2(28e,2h,2e; 12o,5o,8o)/ANO-RCC but thermal corrections are computed with XMS-CASPT2 with (4e,5o).