Objects on the canvas can be moved in pan selection mode.
Place your mouse cursor over the component (or any canvas element thereof) you would like to move
Keep the left mouse button pressed until the preview mode becomes active, then drag until the molecule part reaches the desired position.
Release the mouse button.
If you move your selection on top of a space that is already occupied a red highlight appears. Releasing the selection at this position will make it return to its original position.
C anvas elements are aligned to an invisible grid. If a position on the grid is already occupied, the move will fail.