For the Schrodinger equation for a hydrogen atom, we need to write out: p^2/2m for the electron. If we define our basis states to be a linear discrete array of points, let's say 4 points. 0,d,2d, and 3d, where is some distance, on the order of a Bohr radius. How do I write p as an operator in that positional basis? I kind of have an idea of how to do it, but I don't want to say anything to bias your answers. I'll hear your ideas then tell you what I did.