This effect is responsible for the hydrogen line at 21 centimeters or 1420 Megahertz observed in radio astronomy.  
This effect is responsible for the hydrogen line at 21 centimeters or 1420 Megahertz observed in radio astronomy.  It can also be used in studying coordination complexes to determine delocalization of electrons from the central ion onto ligands.  It occurs because a magnetic nucleus with nonzero spin I can adopt different orientations, giving rise to 2I+1 contributions to the local magnetic field.  Occurring on a much smaller order than a similarly named effect, this is, FTP, what type of splitting structure created by nucleon-electron spin interaction?
This effect is responsible for the hydrogen line at 21 centimeters or 1420 Megahertz observed in radio astronomy.  
hyperfine structure or splitting