Because the Heisenberg Hamiltonian presumes the electrons involved in the exchange coupling are localized in the context of the Heitler–London, or valence bond (VB), theory of chemical bonding, it is an adequate model for explaining the magnetic properties of electrically insulating narrow-band ionic and covalent non-molecular solids where this picture of the bonding is reasonable.
James Bond | The Big Bang Theory | Valence, Drôme | Valence | Theory of a Deadman | James Bond (film series) | music theory | Ward Bond | Brooke Bond | James Bond in film | probability theory | Bond University | bond | theory | Samantha Bond | Nigel Bond | Kit Bond | Edward Bond | Theory of relativity | Bond (finance) | theory of relativity | Social learning theory | Julian Bond | Game Theory (band) | Game Theory | Conspiracy theory | Aymer de Valence, 2nd Earl of Pembroke | William de Valence, 1st Earl of Pembroke | Music theory | K-theory |