2D diagrams are automatically created using our internal processing system (CSD-Xpedite). The systems use the existing data already in the CSD to help define the chemistry in the structure.
If the structure is very complicated or contains unusual chemistry then our systems may struggle to define the chemistry in the structure. In these cases our diagram generation code may timeout and a diagram will then not be displayed during the deposition process. A chemical diagram for the structure will be created by our team of expert scientific editors before the structure is published in the CSD.