Modeling and TEM image simulation. Each experimental TEM image was analyzed through comparison with the simulated images of putative models of QDs seen from various directions. To create the model, it is necessary to determine the angles of observation from the experimental TEM images of QDs that are inclined in three dimensions. The tilts of QDs were calculated mathematically using the two clearly observed edges and the central line. The structure of QDs for the modeling was generated on a Materials Studio software by using reported structural data (CCDC 1446529 for MAPbBr3, mp-600089 for CsPbBr3). Additional models were designed on Blender v.2.93.5. Each experimental TEM image was analyzed through comparison with the simulated images of putative models of QDs seen from various directions. The image simulation was performed by using a multi-slice procedure implemented in a Bionet elbis software . We used the experimental TEM conditions including total electron dose as the parameters for the simulation.