We summarize the properties of the metrics investigated herein in Table . A few points All 1.000 1.000 2.000 0.500 0.500 0.500 0.500 1.000 0.000 are in order to clarify the listed properties: Although UCCSD is of course size-extensive, ⟨S 2 ⟩ UCCSD does not scale with particle number, in contrast to the rest of the metrics. This is not necessarily a bad thing, given that comparisons among molecules of different sizes may require something along the lines of division by N for size-extensive metrics. By orbitalinvariant, we mean that a fixed wavefunction will yield a fixed metric no matter which single-particle orbitals are used to represent it. In addition, an ideal metric that tracks the correlation strength will flag strong correlations that arise due to the need to restore symmetries of the system -not just spin-symmetry but spatial and others as well -and should also be meaningful in the thermodynamic limit (⟨S 2 ⟩ is not a good quantum number in this limit).