Fig. 4: Energy barrier of interlayer sliding between bilayer PbI2.
From: Order-disorder phase transition driven by interlayer sliding in lead iodides
a Ball-and-stick model of bilayer PbI2 shown from the top view. For clarity, the lower layer is shaded, and only one Pb atom in the upper layer (black ball) is shown. b Calculated energy difference of displacing the upper layer with respect to the lower layer and plotted over the same area as in a. The circled A, B, and C show the high-symmetry sites in the lower layer, as defined in Fig. 1a. Red, blue, and yellow arrows indicate 3 representative sliding directions as introduced in a. c, d Energy difference plotted as a function of the layer displacement (c) along blue and red arrows, and (d) along yellow arrow. Source data are provided as a Source Data file.
