The Pauli principle and magnetism

According to Heisenberg ferrmagnetism stems from the Pauli magic mediating between Coulomb interaction and electrons' spins. The primary aim of the paper is to turn the magic into an algebra by setting a precise bound to the degree a given electron density can affect spins. An application of the resulting spin-orbital Pauli constraints to Fe, Co, and Ni provides a new insight into the origin of magnetic moments in this archetypical ferromagnets.