“…Currently, none of the commonly used Monte Carlo codes for radiation transport, e.g., GEANT4 [7,8], PENELOPE [9,10], or MCPNX [11,12] model the interference of coherent scattered photons in diffraction that would allow one to image the electron charge distribution or form factor of the sample. Coherent scatter diffraction is not modeled in most Monte Carlo simulations for two reasons: First, the interatomic spacing or configuration of atoms in the materials is not a single default value; and second, in many Monte Carlo codes such as GEANT4, photons are tracked one at a time in the simulation, so interference between photons or electromagnetic waves cannot be modeled readily.…”