"Ab initio" structure solution from electron diffraction data obtained by a combination of automated diffraction tomography and precession technique

Abstract

Using a combination of our recently developed automated diffraction tomography (ADT) module with precession electron technique (PED), quasi-kinematical 3D diffraction data sets of an inorganic salt (BaSO(4)) were collected. The lattice cell parameters and their orientation within the data sets were found automatically. The extracted intensities were used for "ab initio" structure analysis by direct methods. The data set covered almost the complete set of possible symmetrically equivalent reflections for an orthorhombic structure. The structure solution in one step delivered all heavy (Ba, S) as well as light atoms (O). Results of the structure solution using direct methods, charge flipping and maximum entropy algorithms as well as structure refinement for three different 3D electron diffraction data sets were presented.