Multigrain crystallography
Sørensen HO., Schmidt S., Wright JP., Vaughan GBM., Techert S., Garman EF., Oddershede J., Davaasambu J., Paithankar KS., Gundlach C., Poulsen HF.
We summarize exploratory work on multigrain crystallography. The experimental arrangement comprises a monochromatic beam, a fully illuminated sample with up to several hundred grains in transmission geometry on a rotary table and a 2D detector. Novel algorithms are presented for indexing, integration and filtering with emphasis on handling the complications of spot overlap and the need for on-line analysis. The structure solution and refinement steps are performed by conventional single crystal programs. Simulations are used to verify the algorithms and to probe the overall limitations of the methodology in terms of number of grains, size of unit cell and direct space resolution. First experimental results in the fields of chemistry, structural biology and time-resolved studies in photochemistry are presented. As an outlook, the concept of TotalCrystallography is introduced, defined as the simultaneous characterization of the 3D atomic, and 3D grain-scale structure of polycrystalline specimens with phases of unknown composition and structure. © by Oldenbourg Wissenschaftsverlag, München.