The crystal structure of JUC-557 was analyzed by using its PXRD pattern together with the structural simulation. After a geometrical energy minimization performed on the Materials Studio software package, the unit cell parameters based on an AA stacking sql net were obtained (a = 35.0907 Å, b = 41.6802 Å, c = 4.0831 Å, and α = β = γ = 90°). The experimental PXRD peaks were well consistent with the simulated ones (Fig. ). Full profile pattern matching (Pawley) refinement was also implemented. It featured three main peaks at 2θ = 3.3, 6.5, and 9.8°, assigned to the (110), (220), and (330) Bragg peaks of the space group P222 (No. 16). The refinement results revealed that the unit cell parameters were close to ideal agreement factor predictions (wR P = 1.36% and R P = 1.08%). In contrast, the simulated PXRD pattern of an alternative staggered 2D arrangement (AB stacking) showed distinct deviations compared with the experimental (Supplementary Figs. and Tables and). Its porosity and textural characteristics were analyzed based on the nitrogen (N 2 ) adsorption-desorption isotherm at 77 K (Fig. ). A sharp gas uptake was observed at low pressure (below 0.05 P/P 0 ), which reveals its microporous nature. The Brunauer-Emmett-Teller (BET) surface area was 1115 m 2 /g, and the total pore volume was calculated to be 0.637 cm 3 g -1 at P/P 0 = 0.9 (Supplementary Fig. ). The pore-size distributions were estimated by the nonlocal density functional theory (NLDFT) and demonstrated the microporous width of ~1.8 nm, which can match well with that from its crystal structure (Fig. ).