I have a couple of questions about what kind of potentials can be used in Schrödinger's equation:
How about the potential from a magnetic field? Isn't Dirac's equation more appropriate in that case, because it will take spin into account? If I choose to ignore spin and use Schrödinger's with a magnetic potential, do I still get useful results?
How about gravitational potential? What happens if I use e.g., $mgh$ in Schrödinger's equation? Do I still get useful results for e.g, neutrons? Or do people normally don't do that, because gravitation is negligible compared to electric fields?