A 5.0-millisecond snapshot of an MA•QD is shown in Fig. 51 . Individual atoms are seen clearly except those blurred on the edge in the middle, suggesting a motion localized along the edge. Comparison with Cs•QD4 2 in Fig. suggests that more than one Br atom, possibly three atoms, are lost from the corner as expected from the EDX data (Fig. ). The 13.3millisecond video images of 1 shown in Fig. , 5n are more blurred than the 20-millisecond images of 2, hence suggesting higher flexibility of the lattice of 1. These images also support the loss of more than one Br atom from the corner. The outline of the two edges is less uniform than that of the Cs QD, and the several dots due to Br atoms moved during 26.6 milliseconds (yellow arrows). The observed difference between the MA and Cs perovskite agrees with the liquid-like property of the former previously found for bulk materials 52 . acid. (f-j) SMART-EM images of 2 on CNT aggregate (20 milliseconds frame -1 , arbitrary time scale). Conditions: 298 K, 80 kV, Electron dose rate (EDR) = 2.1-2.8 ´ 10 7 e -nm -2 s -1 . Additional pictures can be found in Supplementary Fig. 16-17. (k) ZC-model of 2 illustrating one Br loss (red) found in (f-j), and three Br loss (blue) in (l-n). (l) SMART-EM image of a particle of 1 (5 milliseconds frame -1 taken at the beginning of imaging). (m-n) Two consecutive snapshots of another particle of 1 illustrating the motion of Br atoms on the edges, and the Br loss from the corner (13.3 milliseconds frame -1 ). Yellow arrows show Br atoms in motion. Additional pictures can be found in Supplementary Fig. . Scale bar = 1 nm.