Equations 2-8 are non-dimensionalised as described previously. The resulting nondimensional system of equations is solved using an implicit finite difference method with an exponentially expanding grid (again, as described previously ). We can now see mathematically that the reaction mechanism in Eq. 1 is governed by five parameters (E 0 , k 0 , α, C dl , R u ), and we will collectively denote these parameters by the vector θ. The inverse problem that we wish to solve can be defined as finding the best possible approximation to θ given our measured experimental output trace of the current I data tot versus potential.