Rietveld fitting method is an effective tool for determination of crystallographic site of many materials form the powder diffraction results. These materials include but not limited to oxides, sulfides, nitrides, etc. However, it seems that the crystallographic site of hydrogen in materials that containing H-atoms, especially in metal hydroxides, are difficult to be determined. I do a lot of work on Rietveld fitting of oxide materials with GSAS software. Recently, I found a new faimly of inorganic cationic framework built by orderedly arrangement of rare-earth and transition metal hydroxides ( Dalton Trans., 2018, 47, 3339-3345 ). The basic structure of this family of hydroxides have been determined by single crystal x-ray diffraction technique. However, for most of other compounds with this family of structures, the crystal size is quite small that makes them unfeasible to solve the structure by single crystal diffraction method. I tried to resolve the structures of these new compounds by Rietveld fitting method. However, the crystallographic site of H-atoms is unreasonable after refinning the site of other atoms. Therefore, I want to ask that a probable method to determine the crystallographic site of H-atoms.