Ewald Sphere Construction

X-ray crystallography works out which crystal planes diffract using a purely geometric device: the Ewald sphere. This simulator renders the sphere of reflection in 3D alongside a real reciprocal lattice built from the crystal's actual spacing and symmetry (simple cubic, FCC, or BCC, complete with structure-factor extinction rules). Rotate the crystal — by hand or with Auto-Rotate — and watch reciprocal lattice points sweep into and out of contact with the sphere's surface, each contact marking a real diffracted beam exactly as Bragg's law predicts. Live readouts track the sphere radius (set by X-ray wavelength), the count of simultaneously active reflections, and the Miller indices and scattering angle of the reflection nearest the beam.