Practice question

Bragg's law, nλ = 2d sinθ, mathematically describes constructive interference when monochromatic X-rays reflect from parallel planes of atoms within a crystal lattice. Incident wavelength λ is known from X-ray source, θ is experimentally measured diffraction angle between beam and crystal planes, n represents diffraction order. Rearranging yields d = nλ divided by 2 sinθ, giving spacing between lattice planes which directly corresponds to interatomic distances. Converting measured spot positions into real-space distances via this equation enables building electron density maps and ultimately three-dimensional models of macromolecular architecture.