In this paper, we have investigated a novel dynamically-weighted state-averaged constrained CASSCF(2,2) (DW-SA-cCASSCF(2,2)) electronic structure approach for studying open quantum systems and in particular molecules on metal surfaces. We have focused on this approach after several aborted attempts with other methods. For several reasons, the present method seems to be an excellent candidate for future work navigating electron transfer at a metal surface: (i) The adiabatic energies are smooth as a result of state-averaging and implementing a constraint that forces the active space to overlap with the impurity; (ii) Diabatization is possible and Marcus curves can be generated; (iii) The approach overlaps well with standard CASSCF theory and we can employ (with modification) many standard quantum chemistry tools to solve the necessary equations. In the end, although DW-SA-cCASSCF(2,2) wavefunctions are slightly more involved than standard multireference approaches, the active space is small and convergence can be achieved.