I get the file through CIF. But still I don’t know how I can create the vertically stacked diagrams or combine simulated PXRD file with as-made one to make a single image using mercury. Do you introduce a route for this purpose in the mercury?
Not in Mercury I'm afraid. I do "stacked lines by y offset" in Origin. I am aware you may not have a licence for this though.
I guess you could does this in excel (I would imagine you'd have to manually add the offset to the raw data), or libre office if you do not have a licence for excel.