I think this will partially help you

http://www.physics.rutgers.edu/ugrad/389/xrays/exp.pdf

One can get those parameters from powder data. You have first know the space group of the crystal, which in most cases are available. One can find bond length and angle from it. 

You can also learn Fullprof program where you can perform profile fitting and determine the lattice parameter more precisely. 

Hi sandeep,

Thanks for your reply. I have got full prof software. How to calculate the parameters from it. any manuals available for it?

Manual is there with software. Goto help and in dropdown menu you will get it.

Dear sandeep,

Thanks for your help.

Yes you can get these structural information by doing Rietveld refinement of the Bragg intensities. But you must know what your sample is and should have a preliminary idea of its space group and structure. The determination of completely unknown structure is also sometimes possible but is difficult.

Dear Tapan,

Thanks for your reply. Can you give me some more explanation with some examples so that I can learn it to do.

Thanks...........