In 1926, Erwin Schrödinger published the equation that describes how quantum systems evolve in time. A century later it remains the foundation of quantum mechanics, and for the most interesting problems it remains out of reach.

Writing the equation down is one thing. Solving it is another. The space of possible states grows exponentially with the number of particles, so even a few dozen interacting particles put an exact solution beyond the largest classical supercomputers.

That is the reason PASQuanS2.1 exists. Rather than computing the answer, we build systems of atoms and ions that obey the same equation, and we watch what they do.