Use Power Cell software:

http://www.ccp14.ac.uk/ccp/web-mirrors/powdcell/a_v/v_1/powder/e_cell.html

It is very simple to use and free.

Best regards,

Pedro

I don't understand your question. Can you clarify what you are trying to do?

I have the parameters like site, wyckoff positions and lattice parameters. Can i generate the XRD pattern knowing these data?

Use Power Cell software:

http://www.ccp14.ac.uk/ccp/web-mirrors/powdcell/a_v/v_1/powder/e_cell.html

It is very simple to use and free.

Best regards,

Pedro

You can use fullprof software to do so, first using your parameters generate a PCR file and running the same .cif and XRD profile can be generated. 

Dear Dr. Karati,

You can use software Mercury from ccp14.ac.uk website. Using Mercury software Open your cif file resulting from Rietveld refinement and then by using this software you can calculate powder XRD ... On the menu bar 'Calculate' is there after clicking on it you can find 'powder pattern' menu click on it.. that will help you to calculate powder pattern.. which you can export in the form of csv or txt format... Secondly your Rietveld profile fitting is already having this calculated XRD in it. Just Export the plot of it and in origin you can check which is observed and which is calculated one...

Dear Colleagues,

Thank You very much for all your suggestions!