The crystal structure of the superconducting (ND3)(x)NaA(2)C(60) (0.7 less than or equal to x less than or equal to 1, A=K, Rb) fullerides (T-c=6-15 K) has been studied by synchrotron X-ray and neutron powder diffraction. It is face-centered cubic (fcc) to low temperatures with Na+-ND3 pairs residing in the octahedral interstices. These are disordered over the corners of two "interpenetrating" cubes with the Na+ ions and the N atoms displaced by similar to2.0 Angstrom and similar to0.5 Angstrom from the center of the site and statically disordered over the corners of the inner and outer cube, respectively. Close contacts between the D atoms of the ND3 molecules and electron rich 6:6 C-C bonds of neighboring C-60 units provide the signature of weak N-D...pi hydrogen-bonding interactions, which control the intermolecular packing in the crystal and may determine the unusual superconducting properties.