diffraction neutronique

CONT: En réalité la seule méthode capable de déceler la structure atomique de la plupart des macromolécules est la diffraction des rayons X par des cristaux. [...] La diffraction neutronique est surtout utilisée pour placer les atomes d'hydrogène, trop légers pour être normalement détectés par diffraction des rayons X, dans des modèles atomiques obtenus par cette dernière méthode.

CONT: Because elements that are close to each other in the Periodic Table differ considerably in their neutron-scattering ability, neutron diffraction is capable of distinguishing between them. For example, carbon nitrogen, and oxygen atoms can be readily identified by neutron diffraction, where as they appear almost identical by the x-ray method. More accurate determination of the bond lengths of light atoms and distribution of molecular bonding electrons is also possible. Details of molecular structure that can only be inferred by other techniques can often be observed directly by neutron diffraction. Investigations using this method include hydrogen bonding, so-called metal cluster compounds (C.H.M relationships) and electronic charge distributions.