Preferred oriented cation configurations in high pressure phases IV and V of methylammonium lead iodide perovskite.

A microscopic viewpoint of structure and dipolar configurations in hybrid organic-inorganic perovskites is crucial to understanding their stability and phase transitions. The necessity of incorporating dispersion interactions in the state-of-the-art density functional theory for the [Formula: see text] perovskite (MAPI) is demonstrated in this work. Some of the vdW methods were selected to evaluate the corresponding energetics properties of the cubic MAPI with various azimuthally rotated MA organic cation orientations.

The crucial role of density functional nonlocality and on-axis CHNH rotation induced I formation in hybrid organic-inorganic CHNHPbI cubic perovskite.

Effects of electronic nonlocality in density functional theory study of structural and energetic properties of a pseudocubic CHNHPbI are investigated by considering coherent rotation around C-N axis of a CHNH cation. A number of truly non-local and semi-local exchange correlation density functionals are examined by comparing calculated structural parameters with experimental results. The vdW-DF-cx which takes into account the non-local van der Waals correlation and consistent exchange shows the best overall performance for density functional theory study of this system.