Crystal structure redetermination of ε-Ni3Si2 from a single nanowire by dynamical refinement of precession electron diffraction data

Accurate crystal structure of single nanocrystals as small as tens of nanometers can be obtained by the recently published full dynamical structure refinement of precession electron diffraction tomography (PEDT) data. Here we apply the method to the structure redetermination of the nickel silicide ε-Ni3Si2 from a nanowire with the diameter of 35 nm. The structure was determined as centrosymmetric Cmcm, in disagreement with the published structure, which was determined by single crystal X-ray diffraction in 1961 in the noncentrosymmetric space group Cmc21. The structure was also determined by single crystal X-ray diffraction (SCXRD), giving the same results as PEDT. The average difference of the atomic positions between the models obtained by PEDT and SCXRD was smaller than 0.007 Å.