My initial answer was incorrect; I hadn’t read the question properly.
Quantum physics involves simulation-based work, given that the fundamental theory—the Schrödinger equation—has already been sufficiently verified through experiments. However, there are numerous complex applications, such as “predicting” material properties, where simulations are employed. These simulations “round out” the theory and consistently provide added insight.
Since the simulations themselves appear highly theoretical, they are easily categorized as a theoretical activity.