Note that I41/amd has two common settings, sometimes (like in icsd) indicated as S and Z, where I think S is the first setting according to ITC-A and Z is the second one. Your database entry uses the 1st setting, but apparently GSAS uses the second one, although it also has an s in the symbol you show indicates something different. Check for this.

Dear Mr. Leineweber,

Thank you for your answer. I changed the space group as shown in attached. Whatever, I changed to amds or amdz, but it does not work. So I will be appreciated if you can give me some other suggestions. As a beginner, I need your suggestions. Thanks. Andreas Leineweber

I haven't used GSAS for years, so I am not familiar with the GUI. However, some programs, if you change the space group setting, also change the xyz (here due to the shift in origin). Check what has changed with the fractional coordinates. Change them by hand appropriately. Check also whether you have access to the individual symmetry operations for control of the setting (if -x, -y,-z is in the list, you have the second centrosymmetric setting).

Andreas Leineweber Thank you , sir. I will have a try.