Diagram provides flexible control over spacing between shapes on the diagram. You can proportionally increase and decrease horizontal and vertical spacing between the shapes, make it equal or remove it.
To increase spacing between shapes, select shapes, which will be moved, and click Increase Horizontal Spacing or Increase Vertical Spacing on the Layout toolbar or choose Increase from the Horizontal Spacing or Vertical Spacing submenu of the Layout menu.
When increasing or decreasing spacing or making it equal, spacing is considered as distance between centers of shapes. But when removing spacing it is considered as distance between shape borders. When you remove, for example, vertical spacing, shapes will be located in the following way: the top of the second shape will be located at the same height as the bottom of the highest shape, the top of the third one will be located at the same height as the bottom of the second shape and so on.