Such stability is obviously desirable so its worth noting that exciton properties such as d e-h , d exc , d CD1 , σ hole , etc., which were introduced in Section 2 .3, are inherently stable because they are formulated as expectation values. Results for a few of these invariant metrics are also shown in Table , confirming this stability. Note also that these exciton properties are no more expensive to compute than ∆r or ∆σ yet there is no ambiguity regarding which representation is the best choice because proper expectation values are invariant to unitary transformations of the MOs.