In the following discussion, we will present several examples that reveal how the representation dependence of metrics such as Λ, Γ, ∆r, and ∆σ negatively impacts their use as measures of CT character and/or exciton size. We first consider a catastrophic example (Section 4 .1) where diffuse basis functions lead to nonsensical results for a compact valence transition. In Section 4 .2, we consider how different choices for the MOs impact the use of Λ and Γ as metrics for assessing CT character, in the sense that was originally envisaged by Tozer and coworkers and by Guido et al.. In Section 4 .3, we consider several examples that cannot be reduced to a single NTO pair (because λ 2 2 0), which is not uncommon in conjugated polymers. These examples demonstrate that ∆r and Γ may lose their simple physical interpretation in such cases. Finally, Section 4 .4 considers a set of CT complexes in which the S 1 state is well described by electron transfer from the highest occupied MO (HOMO) of a donor molecule into the lowest unoccupied MO (LUMO) of its partner. These examples highlight that Γ NTO does have intuitive and interpretative value in this idealized case.