摘要: Amorphous solids, which do not possess the long-range order, hold great promise in mechanical, optical, and chemical properties, etc., and have also been revealed as critical biomineralization precursors. However, fundamental questions about their three-dimensional (3D) atomic structure remain challenging due to the long-range disorder. Conventional protocols probe such molecular structures through scattering or real-space imaging. The former provides ensemble-averaged data that masks local structural deviations, while the latter is hampered by the electron-beam sensitivity of materials. Nevertheless, based on distance-sensitive heteronuclear coupling, rotational echo double resonance (REDOR), a specialized solid-state nuclear magnetic resonance (NMR) measurement, is efficient in detecting local deviations and usually nondestructive. Here, using amorphous calcium carbonate/phosphate Ca(CO3)x(PO4)2(1-x)/3 (0 < x <1, CaCPs) solids synthesized by ion cross-linking as an example, we develop a nondestructive method to reveal local deviations of amorphous ionic solids by combining REDOR, Monte Carlo (MC), and molecular dynamic (MD) simulation. Briefly, MC simulations generated atomic structures with heterogeneous medium-range spatial apportionment of ions, and MD simulations relaxed the initial configuration to rationalize short-range order. Then, theoretical REDOR decay curves of MC/MD-generated structures were compared with experimental values to check the medium-range order. We revealed that there was heterogeneous medium-range spatial apportionment of anions in CaCPs. Because solid-state NMR applies to virtually any spin-bearing material, this methodology provides an alternative route to resolve the atomic structure of amorphous solids.