The phenomenon of interfacial electron transfer at a metal surface lies at the heart of Marcus's electrochemical rate theory and in recent years our research group and others have made a broad push to model such dynamics semiclassically (as applicable to large systems). While quite a bit of progress has been made to date, the inevitable practical problem that arises is not of a dynamical nature but rather of an electronic structure nature. How can we best (and most quickly) describe the electronic wavefunction of a molecule at an interface, especially if there is strong molecule-metal coupling? The usual frameworks would be GW methods, embedding methods, constrained DFT, and/or ∆SCF. That being said, recently we introduced an orthogonal approach. Namely, we showed early data suggesting that a small CASSCF(2,2) calculation (if properly constrained) could function as an excellent method, balancing accuracy and computational speed. The key insight presented in Ref. 48 is that, when constructing such a CASSCF(2,2) approach, one must be sure (i) to constrain the two active orbitals so that their total population has some overlap with the molecule on the surface; and (ii) to use state-averaging so as to balance the gap between the ground and excited state and make smooth surfaces. If one implements these guidelines, Ref. 48 demonstrates that the resulting algorithm can seemingly perform quite well (at least for those models tested).