Decoding Van der Waals Impact on Chirality Transfer in Perovskite Structures: Density Functional Theory Insights

Area of Science:

• Materials Science
• Solid State Physics
• Computational Chemistry

Background:

• Chiral organic-inorganic perovskites possess unique properties due to chiral organic cations.
• Understanding chirality transfer and the role of van der Waals (vdW) interactions is incomplete.

Purpose of the Study:

• Investigate the role of vdW interactions in chirality transfer in perovskites.
• Evaluate various vdW corrections for accuracy in describing chiral perovskite structures.

Main Methods:

• Density Functional Theory (DFT) calculations using Perdew-Burke-Ernzerhof (PBE) functional.
• Application and comparison of multiple vdW corrections (e.g., Grimme, Tkatchenko-Scheffler, MBD).
• Analysis of lattice parameters, binding energies, and charge transfer.

Main Results:

• D3, D3(BJ), TS, TS+SCS, TS+HSI, and MBD vdW corrections accurately describe chiral perovskite structures.
• Identified chirality-induced asymmetries in octahedra, dependent on cation configuration (R or S).
• vdW interactions are crucial for accurately describing these asymmetric distortions and strengthening hydrogen bonds.

Conclusions:

• Accurate vdW interactions are essential for understanding chirality transfer mechanisms in perovskites.
• The study provides insights into structure-property relationships in chiral perovskites.
• Refined understanding of the Rashba-Dresselhaus effect in 2D chiral perovskites.