{"knowledge_schema": {"broad_category": "Materials Science \u2192 Crystallography \u2192 Interplanar Spacing", "refinement": "This problem involves calculating the interplanar distance for a specific crystallographic plane in a rhombohedral crystal structure.", "specific_scope": "The focus is on the (211) plane of a rhombohedral crystal with given interatomic distances and angles.", "goal": "Calculate the interplanar distance of the (211) plane using the provided parameters."}, "summary": "This problem pertains to the field of materials science and crystallography, specifically focusing on the calculation of interplanar distances in a rhombohedral crystal structure. Given the interatomic distance and the angles of the crystal, the task is to determine the distance between the (211) planes. The solution involves applying the appropriate formula for interplanar spacing in a rhombohedral lattice, leading to the conclusion that the interplanar distance for the (211) plane is 7.12 Angstrom."}