In addition to testing the performance of the DVS-APC scheme for this set of transition metal excitations, we also wish to judge the efficiency of the active space selection in terms of choosing only the important orbitals. Because APC relies on a pre-defined maximum active space size, the approach can often select an active space that is larger than needed to provide a qualitative reference for a given system. In addition to increasing the cost of the calculation, selection of an active space that is too large can cause spurious orbital rotations when modeling systems (e.g., in molecular dynamics or reactivity simulations), resulting in active space inconsistency error (ASIE). Here, we explore the idea of "down-sampling" a smaller minimal active space from the converged DVS-APC active spaces on the basis of natural orbital occupations. We define a range of cutoffs, n min dev , in terms of deviations from 0 or 2 occupation, where orbitals which differ by more than the given cutoff remain in the down sampled active space (e.g. with n min dev = 0.01 any orbital with an occupation of greater than 1.99 or less than 0.01 would be removed from the active space). These values are 0.025, 0.02, 0.015, and 0.01. After removing the weakly correlated orbitals, a CASCI calculation is run with the new active space, followed by tPBE, tPBE0, and NEVPT2 energetics. Figure shows the performance of these down sampled active spaces compared to the initial full active space in terms of MAE relative to the TBEs and the size of the average active space. As is seen, a modest occupancy cutoff of 0.01 results in the elimination of about three unnecessary orbitals from the active space with only minimal changes to the performance of the methods. However, increasing the occupancy cutoff any further -even to an occupancy cutoff of 0.015 -results in a significant deterioration of the performance of all methods.