Spin relaxation of conduction electrons in polyvalent metals: A   realistic calculation
  Relaxation of electronic spins in metals is significantly enhanced whenever a Fermi surface crosses Brillouin zone boundaries, special symmetry points, or lines of accidental degeneracy. A realistic calculation shows that if aluminum had one valence electron, its spin relaxation would be slower by nearly two orders of magnitude. This not only solves a longstanding experimental puzzle, but also provides a way of tailoring spin dynamics of electrons in a conduction band. 
J. Fabian and S. Das Sarma