1. Select atom type & click on the canvas to add.
2. Adjust scattering factors with the sliders.
3. Hover over Patterson peaks to see vectors.
Peak area ∝ summed fᵢfⱼ. Boundary copies are the same periodic peak.
Gold: origin; green: AA; cyan: BB; orange: AB; purple: mixed pairs.
Fourier map: finite h,k range causes broad peaks and ringing;
white is positive, blue negative (linear scale). F₀₀ is included
in the transform but hidden in diffraction. Constant real scattering factors;
fractional coordinates and unit cell area = 1.