{"knowledge_schema": {"broad_category": "Science \u2192 Crystallography \u2192 Structural Analysis", "refinement": "This topic involves understanding the principles and metrics used to evaluate crystal structures, including goodness of fit, refinement quality, space groups, and unit cell properties.", "specific_scope": "The focus is on evaluating statements related to crystallographic metrics and properties, particularly in the context of unit cell volume and formula units.", "goal": "Identify the incorrect statement regarding crystallography and understand the relationships between unit cell volume and formula units."}, "summary": "In crystallography, various metrics are used to assess the quality of crystal structures, including the goodness of fit (gof), R1 value, and characteristics of space groups. The unit cell volume (U) is related to the number of formula units (Z) in a cell, but it is not directly proportional; rather, it is influenced by the dimensions of the unit cell and the arrangement of atoms within it. Therefore, the statement claiming direct proportionality between unit cell volume and the number of formula units is incorrect."}