Quantum-based material’s calculations are a simulation activity, not a theoretical activity, because as far as quantum mechanics is concerned, there already exists a theoretical formulation — a set of laws that describe behaviors that are accessible at the experimental level. What is needed now is to employ these laws at a deeper level, to see whether they can help us predict particular behaviors or, as in the case of materials science, to optimize the search for an optimal material that meets the characteristics we want to obtain.