There’s been a few questions of late about the shapes of molecules. You may like to download these (free) software packages which will help you visualise molecules. Accelrys’ “Symyx Draw” (past incarnations were known as ISIS Draw by MDL). All you need to do is do a simple online registration to get Symyx Draw for free. With it, you can sketch any molecule and then after view it in Rasmol where you can visualise molecules in many different ways: glorious 3D and spin them around.

• Install (via registration screen) Accelrys’ “Symyx Draw” 4.0 (they will e-mail it to you at the address you give them)

• Rasmol (or RasWin if you use windoze) Molecular Graphics Visualisation Tool

Note: you sketch the molecule in Symyx Draw. Save as molfile (.mol) and then use Rasmol to load the mol file format and see it in 3D. (in display, choose spacefill)