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Dear Rex, 1. What are the limits to data set completeness imposed by a Laue experiment versus those of monochromatic data collection? Laue allows for a greater number of Bragg reflections to be measured compared to monochromatic data collection over a give time period. The limiting factor in neutron crystallography in regards to data completeness is predominately collection time and instrumentation (detector size). 2. What problems are caused by flash freezing the larger protein crystals used for neutron data collection which do not occur for X-ray data collection ie because smaller crystals can be used. Any help will be greatly appreciated. In my hands, flash cooling becomes more difficult as the crystal size increases due to the volume that must achieve the glass transition state (must be fast and well centered in the cryogenic stream). I would reach out to the beamline scientist, if you are serious considering collecting at a macromolecular neutron beamline using cryogenic temperatures. Most data collections with neutrons are measured in days with some up to a month and don't believe any neutron beam lines have an automated refill system of liquid nitrogen. I hope that helps. Take Care, Sean Seaver P212121 http://store.p212121.com/