Back to the overview of different vitamins When you can not open the PDB files you probably have not the free plug-in Chime. You can download Chime, after registration, free of charge by clicking here. Vitamine A Chemische naam: Retinol of All-Trans-Retinol Molecuul formule: C20H30O Traditionele structuurformule.   3D-ball & stick structuurformule. De PDB file getoont met Chime.