Thank you, sir. I got 3 twin data sets. Can i write one after another in the .ins file? Or need to do something else. In another data i got one value as 0 0 0, 0 1 0 and 0 -0.5 -1. How to treat -0.5 value? It shows a parameter out of range. Kindly help And in other method of twinning in olex2, one -1/2 is coming for k value but after refinement nothing changed just r integral is showing as n/a.