Quantum-based materials calculations rely on numerical algorithms and computational approximations to solve the Schrödinger equation for real systems, which is intractable analytically. These methods produce data-driven predictions that are validated against experiments, making them simulations rather than purely theoretical constructs.

why do many people have the opposite idea?
Many associate “quantum” with abstract theory (like wavefunctions or entanglement) rather than practical computation, and the term “theory” in “quantum theory” reinforces this. Additionally, the mathematical complexity of quantum mechanics can obscure the fact that most modern applications require brute-force simulation to bridge theory and observable reality.