The constrained local moment theory , like quantum molecular dynamics is based a the separation of fast and slow degrees of freedom. In this case, the fast electronic degree of freedom is the process of forming an atomic site magnetic moment. This occurs by an electron hopping to an atomic site, interacting with it and leaving it with a fixed magnetic moment. This process occurs on a time scale of ~10^-15 seconds. The slow degree of freedom is dynamical process of moment reorientation, better known as a spin-wave. The dynamical time scale of this process is of the order of 10^-13 seconds. Therefore, a fixed finite magnetic moment exists for each atomic site for time t between 10^-15 and 10^-13 seconds.

Fast degree freedom: An electron hops to a site and interacts with it and leaves it with a fixed magnetic moment. This represents the fast electronic degree of freedom of magnetic moment formation.	Slow degree of freedom: Spin waves are elementary excitations where the ends of the spin vectors precess on the surface of cones, with successive spins advanced in phase by a constant angle. This represents the slow orientational degree of freedom.