Occupancies of an atom or fragment split over two sites?
Use constraints. Constraints are set up using List 12, so you must be prepared to eschew the GUIDE and write your own constraint instructions. Here is how: Step one: Before you do anything, ensure that the occupancies of the two sites add up to one. A constraint only affects the shifts applied to parameters: if the sum of the parameters is not sensible to begin with, it never will be. There are several ways to do this.
