I am seeking cif file on KMg2H(PO4)2 ·15H2O,it would be a serious need if anyone could help me with cif file or XRD or any other type KMg2H(PO4)2 ·15H2O.
Fairly comprehensive answer was provided in multiple other threads for databases which I direct you to them. In general, you can look at places like the crystallographic open database (COD) or American Mineralogist. SREC also provides a complete and upkept list of free crystallographic databases. These will allow you to search the composition you are looking for. The only caveat is that you need to check the structures that you use, with something like VESTA.