Variation in the Spin-Splitting Magnitude from Dynamic Structural Distortions in 2D Hybrid Perovskites

The observation of finite Rashba/Dresselhaus spin splitting in hybrid organic–inorganic halide perovskites (HOIPs) makes them attractive candidates for spintronic and spin-selective applications. However, HOIPs are highly dynamic crystals exhibiting complex octahedral tilting and strong anharmonic distortions. In this work, we investigate how these dynamic distortions influence the calculated spin splitting, Δ E ± . Using molecular dynamics simulations with machine-learned interatomic potentials (MLIPs) at T = 300 K, we find that Δ E ± can change by up to ±0.11 eV for eight previously studied systems. We then introduce dynamical structural descriptors and apply them to screen 21 experimentally reported non-centrosymmetric HOIPs, predicting significant spin splitting (Δ E ± ≥ 0.02 eV) in 12 compounds. For many materials, the maximum Δ E ± reached during dynamic fluctuations exceeds that of the time-averaged (experimental) structure. Notably, even systems with Δ E ± = 0 in the static structure exhibit finite Δ E ± dynamically. These results highlight the importance of dynamic structural effects when considering spin-selective phenomena.