Crystal Diffraction (Bragg's Law) Simulator

Crystals are built from atoms arranged on a periodic lattice, and that periodicity is exactly what makes X-ray diffraction work: waves reflecting off successive atomic planes interfere constructively only at specific angles set by Bragg's law, nλ = 2d·sinθ. This simulator renders a real 3D simple-cubic, body-centered-cubic or face-centered-cubic lattice, fires a beam at a chosen grazing angle, and lights up the diffracted beam whenever the path-length difference between planes lands on a whole number of wavelengths. Tune the lattice constant, wavelength and angle — or let the angle sweep automatically — to see how the allowed reflections shift with crystal structure, exactly as they do in real X-ray crystallography.