Replacing an existing atom

After selecting a structure from the structure menu, the structure will replace any double-clicked atom. So, to change a methane into an ethane, select the methyl structure and double-click on one of the methane hydrogens.

You can add structures in the same way using the atom pop-up menu. By right clicking on an atom (or selection), you can choose a structure from the pop-up menu. The atom (or every atom in the selection) will be replaced by the structure. This feature will not work with the metal-complexes and whole amino acids.

If you press spacebar, the last structure tool is selected again. You can then directly use it again by double-clicking on another atom.