To gain further insights into the crystallinity of Zn2(bim)4 film, the GIWAXS configuration was optimized by changing the rotation angle of the sample (ω) with the incident angle (α) from 0 to 0.3° (Fig. and Supplementary Fig. ). A double peak effect becomes pronounced for α in the range of 0.06°-0.14° (Fig. , h, Supplementary Fig. ). Supplementary Fig. depicts the beam trajectories responsible for the observed dual peak phenomenon. This occurs due to deviations in the paths of the beam as it interacts with the film: either first scattered, then reflected from the substrate, or vice versa. At an angle (α) of 0.14°, the dual peaks converge, shifting towards higher q values as α increases (see Supplementary Fig. ). This optical phenomenon provides further support for the assertion that the Zn2(bim)4 film exhibits uniform and homogeneous epitaxial deposition and high crystallinity when deposited on graphitic substrates. Meanwhile, at an incidence angle exceeding 0.16°, a robust and broad peak emerges within a q value range of approximately 1.0-2.5 Å -1 , lacking any discernible orientation (Fig. , Supplementary Fig. ). This peak corresponds to the amorphous SiO2 layer on the Si wafer (Supplementary Fig. ). GIWAXS patterns of the Zn2(bim)4 film at various incidence angles (α). The incidence angle was adjusted by altering the rotation angle (ω) and determined by calculating the angle difference between the sample surface and the beam (for details, see Supplementary Fig. ). The area circled by black dashed line shows the wide and nonoriented peaks derives from amorphous SiO2 on the substrate (Supplementary Fig. ). (h) The intensity of the 002 peak of Zn2(bim)4 film at three incidence angles at 0.02° (top, grey), 0.10° (middle, orange) and 0.18° (bottom, blue).