ABSTRACT
To "see" an object we shine radiation on it. The object scatters this radiation, some of which is received and processed by the eye and the brain, or by some other recording and interpreting device. Determining the internal structure of a crystal amounts to "seeing" it on an atomic scale. Since the sizes of atoms, as well as their typical separations, are in the Angstrom range, the radiation employed should also have a wavelength in this range. X-rays, thermal neutrons, and electron beams are commonly used for this purpose.
