Debye–Waller factor

The Debye–Waller factor, also known as the thermal factor or the static form factor, quantifies the effect of atomic vibrations on the scattering of neutrons or X-rays by a crystalline material. Specifically, it describes how much the intensity of scattered X-rays or neutrons is reduced due to the thermal motion of atoms within a crystal lattice. In a crystalline solid, atoms are not stationary but vibrate about their equilibrium positions due to thermal energy.