Add lone pairs

I wonder whether there is any way to add lone pairs individually to atoms? I am using MarvinSketch for chemical mechanism drawings, and I can currently see no way to add lone pairs just to a particular atom, for example a nucleophile in an addition reaction. 

Dear Dominic,

firstly I would suggest that you select View<Advanced<Lone Pairs.

Additionally, you can add the Lone Pair Group button to your toolbar of choice:

View<Editor Style < Customize < Toolbars tab. Here from that drop down menu select the toolbar which you want to the button add to. From the Toolbar Contents pane press "Add...". In the Add commands window choose "Insert Lone Pair Group" then from the Command select "Lone Pair Group" then press "Add". Now close the window, press "OK" the underlying one.

If you need to add radicals, those can be added from the contextual or the Atom menu (the atom  should be selected).

Please let me know if you have any questions.

Best regards,

Nikolett Mihala

I have added the Lone Pairs Group to my toolbar, but it is greyed out, even when I have selected an atom. How do I make this work? 

Sorry, one more thing:  Automatic Lone Pair calculation should be disabled on Edit<Preferences<Structure tab.

Thanks very much, all working now.