I have created a simulation of one electron bouncing through a 3D mesh of molecules. The electron hopping is determined by a calculation of electron transfer rate using the Marcus equation (a result in units of $1/s$). In order to force the electron to reach one end of this 3D mesh I have applied a driving energy $dE$ (negative) to each molecule.
I am familiar with the electric field equation but I do not see how it applies to one electron bouncing through many molecules. How do I go about calculating the electric field that I applied?