Fig. 2: Packing modes and entanglement of hxl 2D layers for 1Ag and 1Au.

a ABCD stacking pattern of 2D layers for 1Ag. Four colors (red, blue, gray and purple) are used to illustrate interlocking adjacent 2D layers. b ABAB stacking pattern of 2D layers for 1Au. c, d Illustration of parallel polycatenation in 1Ag and 1Au. Hydrogen atoms and solvent molecules are omitted for clarity.