Summary Molecule structure STL files are generated by OpenSCAD, of which program is generated by "sdf2scad.perl" Perl script from NCBI PubChem database (3D SDF format files). About generating scripts and note, see http://www.thingiverse.com/thing:689652 (Water and Ethanol). Here are two chemical materials which keeps you awake and invite for sleeping - caffeine (C8H10N4O2) and melatonin (C13H16N2O2). Both beautiful. Construction 3D data (SDF file) is from the PubChem Project https://pubchem.ncbi.nlm.nih.gov/ . Instructions See http://www.thingiverse.com/thing:689652 (Water and Ethanol) for detail. I used Microsoft Model Repair Service (https://modelrepair.azurewebsites.net/ , need MS account) for generated STL using OpenSCAD. The melatonin is my first work in this series. I used black & white filament for carbon & other atoms, but because of contamination, it's not so beautiful (as you see in the picture). However, if you would like to make separated STL files & use dual extruder printer, please read the Instructions in "Water and Ethanol" http://www.thingiverse.com/thing:689652 . The caffeine is made using only white filament, then painted black. As you see in the picture, it's more beautiful than melatonin which uses dual filament (white & black). (^_^;)