As shown, a distinct peak appears at 1.7 nm which is followed by smaller peaks at 2.4 and 3.2 nm. The 1.7 nm is close to the repeating pattern of BT in polymer chain, with a similar backbone feature shown in the simulated scattering pattern at q = 0.4 Å -1 (d ≈ 1.6 nm). Note that 0.1 nm difference can be explained by the slightly different position of centre of mass of two BTs belong to different chains as compared to two adjacent BTs in one chain. 3.2 and 2.4 nm are close to 2d and √2d, respectively. Also, by pulling out the crossing points contributing to the (small) peak at 0.8 nm, we noticed that it is due to the (rare) π-π interaction between four BT molecules at crossing points so that the average distance between centres of mass of the two BT pair is about 0.8 nm. Note that we observed that >95% of the BT-BT crossing do not show the stacking of more than 2 chains. Considering the preferential perpendicular chain alignment at BT-BT crossings and the peaks in the rdf, a mesh-like chain arrangement model as shown in Figure seems possible. It should be noted that the cartoon shown in Figure is excessively idealised and the 3D arrangement of the chains only show a slight preference to (rather than having an exact) squared lattice structure.