Although we have proposed construction of active spaces via the diagonalization of F -λK in the space of Hartree-Fock virtual orbitals followed by APC-based entropy calculations, the procedure of variational tPBE selection among trial wave functions can be combined with other schemes for constructing multiconfiguration wave functions. We note that although the scheme has proved successful for the excitations shown here, we expect that applying the scheme to metal-containing systems and adiabatic excitations may require additional development. Nevertheless, a specific strength of this approach for applications with a large number of orbitals is that it forgoes the costly step of multiconfgurational orbital optimization.