Ubiquitous Short-Range Distortion of Hybrid Perovskites and Hydrogen-Bonding Role: The MAPbCl3 Case

The local structure of MAPbCl3 has been investigated through the combined use of X-ray and neutron pair distribution function (PDF) analysis and computational modeling. The results indicate the presence of a significant level of distortion at the short-range, irrespective of the average structure found by diffraction, and this suggests a possible correlation between the type of distortion and the features of the strongest H-X bond. The distortion of the octahedra decreases by reducing temperature, but the overall tilting of the octahedral system increases, and such tilting depends on the size of the anion. The comparison of the short-range structural data available on the MAPbX3 family strongly indicates a common pattern of the local structural distortion in these systems.