We determined the structure of Ni(PyC-m-NH 2 ) 2 from its X-ray powder diffraction (XRPD) pattern measured with Cu-Kα 1 radiation at room temperature after re-activation at K for h. See Sec. . . for detailed methods. Similar to Ni(PyC) 2 [ ], Ni(PyC-m-NH 2 ) 2 shows a two-fold interpenetrated diamondoid network in a unit cell with space group symmetry P nn2 (no. ). As further evidence of a two-fold interpenetrated network, simulated Xe adsorption in a two-fold interpenetrated Ni(PyC-m-NH 2 ) 2 structure model matches the experimentally measured adsorption significantly better than in a single network Ni(PyC-m-NH 2 ) 2 structure model; see Sec.S . . Fig. shows the experimentally determined Ni(PyC-m-NH 2 ) 2 crystal structure. A cis configuration of the carboxylates coordinating Ni is preferred, as in Ni(PyC) 2 . We also tested the trans configuration with a space group symmetry of P 2 1 {n (no. ), but it resulted in significantly poorer agreement with the XRPD pattern.