# Structure recovery from angular correlations of intensities

# Structure recovery from angular correlations of intensities

A circumstance where the angular correlation are useful in the attempt to recover structure from randomly oriented particles in an XFEL. We will show that in this case the number of particles illuminated is almost irrelevant.This is particularly important since x-ray are not strong scatterers off matter. In x-ray crystallography, when x-ray scatter off crystals they scatter off trillions of molecules. Yet reconstructed is just a single molecule. This enables something similar to happen with disordered molecules. to overcome the intensity deficit. Note that we can work with incoherent intensities. because correlations allow the recovery of phases as Hanbury Brown and Twiss showed in astronomy. Note that two distinct algorithms are proposed from the recovery of structure from correlations. The method of Kam and Saldin et al, which depends on the great othogonality theorem of group theory, and the method of Kurta et al. which depends on the convolution theorem. I am particulary interested in the latter method as it allows for the possibility of finding the full solution to the phase problem.