H ... I distance shown in (A) with respect to the increase of the branch length within TMHPs (the horizontal dashed line indicates the summation of the van der Waals radii of H and I atoms [~3.1 A]). The large fluctuation of the H ... I distance of (BBA)PbI4 originates from the disorder of the organic cations in the single-crystal sample. Data are represented as mean ± SD.
