The combined 10899 ligands in the OE and EXP series were subjected to DFT geometry optimization and MD simulations for stability characterization. MD simulations were initialized in an ideal single layer (n=1) 2D Ruddlesden-Popper phase PbI4-perovskite structure followed by a 200 ps equilibration (see Methods in SI for additional details). The same approach could be extended to n>1, other halides, and other metals, but these variables are beyond the scope of the current study. This MD approach has been adopted in several recent joint experimental studies for studying water penetration and ion diffusion in 2D halide perovskites with distinct ligands for comparisons with experiments. All simulations were conducted using an L2PbI4 composition, where L is the simulated ligand. The distortion of the Pb-I octahedra in these simulations was used as a stability metric for each ligand-perovskite combination (Figure ). The octahedral distortion was quantified based on bond length quadratic elongation (∆⟨λ⟩) and bond-angle deviance (∆⟨σ 2 ⟩) from their ideal values in a perfect perovskite structure where ⟨λ⟩ and ⟨σ 2 ⟩are defined as