Structural features extracted from the electron tomographic data. 3D model and typical 2D TEM image extracted from the tilt series of a (a) TH500 agglomerate; (b) D40 agglomerate; (c) D10F4 agglomerate; (d) C200 agglomerate; and (e) two types of aggregates formed as part of different interactions between crystallite surfaces: F1, F2, F3, F4 – Schematic representations of the basal and lateral face interactions between various crystallites.