What does Chem3D mobile's Export STL do? Are there any limits on the size of a structure exported in an STL file?
Export STL is used to generate a representation of the molecule suitable for input to most 3D printers. There are two types of STL file: text and binary, and Chem3D exports the binary version. The STL file is written to the user's local documents directory and can be retrieved via iTunes.
Details of the STL format can be found on this Wikipedia page:
At present, the molecule is written out with no color information, so the printed molecule will take the default color of the specific 3D printer used.
Since STL files can get very large, an upper limit of 500 atoms is placed on the STL export feature.