By clicking and dragging on an empty spot and dragging a selection frame is shown. Everything within this frame gets selected.
By holding the shift key more elements can be added or removed to a selction by clicking on elements or click-dragging a second selection frame.
Depending on the selected element small scaling boxes in the corners of the selection or a rotation knob are shown.
Selected objects can be grouped or arranged in different manners from the mainmenu item "arrange".
If you click or select an object of a group all grouped objects will be selected automatically.
To move selected elements just click somewhere inside the selection frame and drag the selection around.
If a selected atoms or molecules are moved over other atoms, intersecting atoms are highlighted. By releasing the selection the molecules are combined at these intersection points.
If visible, just click on a controlpoint of the selection frame and drag around. The selection gets scaled. By holding the shift key width and height scaling is identical.