To show that the DVS-APC procedure is applicable to transition metal systems beyond diatomics, we evaluate its performance in modeling the excited states of two larger transition metal complexes: MnO - 4 and [Cr(CN) 6 ] 3-. The DVS-selected orbitals for MnO - 4 and [Cr(CN) 6 ] 3-are presented in Figure . For the permanganate ion, past work from Sharma et al. uses an active space including all valence electrons except for the 2s electrons on the oxygen atoms and 5 additional virtual orbitals, for a (24,17) active space. Another study makes use of an active space of the same size. Applying DVS-APC with a maximum (15,15) active space and trial wave functions generated by N = [4, 8] and λ = [0, 0.5, 1, 1.5, 2] yields a qualitatively identical active space. Examination of the resulting active space at smaller maximum sizes led to the final choice of a (15,15) maximum size. In particular, the DVS-APC results with a (14,14) maximum produced an active space of (24,16) which was nearly identical to the reference active space, but missing one virtual orbital due to the size constraint (Supporting Information).