Origin of Magnetism 90 Years of Misunderstanding

After Slater published his paper on Hund’s rule, almost all standard textbooks follow his idea of explaining the origin of magnetism (the reason of stabilization of the magnetic ground state) based on electron exchange energy. However, when his theory was invented, computer was not available to numerically solve many-body electron system, and he omitted the most important contribution from the nucleus–electron interaction (nucleus charge has a sharp peak, but he assumed uniform distribution). We have proved that this omission makes a serious problem of violation of virial theorem, which is a necessary condition for any Coulomb system. We have solved the Schrödinger equation numerically satisfying the virial theorem and proved that the contribution of the nucleus–electron interaction is the fundamental part to reduce the energy for magnetic ground state. Based on the virial theorem satisfaction, we can now distinguish correct and incorrect theories. Most striking fact is that the two-level models assuming the same space wavefuntions such as Hubbard model is incorrect and they should be excluded from the theory of magnetism.