Planar stacking analysis was performed using bespoke code tailored for this purpose, using molecular planes of best fit (PBFs). The PBF of a molecule is calculated from the principal components of the molecule, taken via singular value decomposition (SVD) i.e. 𝑴 = 𝑼𝚺𝐕 * where 𝑴 is the matrix of atomic positions in the molecule. SVD yields the principal components of the molecule, which can be sorted by their corresponding singular values 𝚺. The least significant principal component N corresponds to the plane normal, and once atomic positions are projected onto this plane via dot product 𝑵 ⋅ 𝑥 a bounding rectangle may be evaluated using the remaining two principal components by finding the extrema of the atomic positions when projected onto this plane.