This animation is a plot of f1 = f0 + f’, and f2 = f” v photon energy. The default element is Ga (Z = 31), though the user can enter his/her own data file. This should have the format of columns hv, f1, f2. The default data file for Ga is provided here. Below the plot is a vector plot of f0 (red arrow), f’ (blue arrow), f” (green arrow), and the total form factor (black arrow). Note that f1, the blue curve in the plot is represented by the vector sum of f0 and f’.
Plot of f1 and f2 v photon energy and their impact on the total atomic form factor