How do I place a single atom in the Workspace?
You can place a single atom in the Workspace with the Draw tool (pencil) on the Build toolbar. Select the atom type from the button menu, then double-click in the Workspace. If you want an atom of a different type, you can change it from the Build toolbar (Set Element button) or in the Atom Properties tab of the Build panel.
If you are placing a metal, you can use the Metal Centers fragment type in the Fragments tab of the Build panel, then change the atom to the appropriate element.