Fig. 5: The ideal atomic representative model for a larger scale picture of IP state.

a Pb displacements represented by arrows vary across an APB. Pb displacements without horizontal components in APB are highlighted by green arrows. b Oxygen octahedral tilts represented by gradation of color vary across an APB. Oxygen octahedral tilts with zero value in APB are highlighted by green colour. c A schematic profile illustrates combination of gradient oscillation of Pb horizontal displacements and oxygen octahedra tilts across an APB.