Why do you need this? Gamma-Fe is a simple structure (SG: Fm3m) with a well-documented lattice parameter (a = 3.647Å), from which the peak positions are trivial to calculate.

The relative intensities are easily calculated also. If you have access to a copy of Cullity's Elements of X-Ray Diffraction, look at Chapter 4, section 13 and Table 4-2.

Why do you need this? Gamma-Fe is a simple structure (SG: Fm3m) with a well-documented lattice parameter (a = 3.647Å), from which the peak positions are trivial to calculate.

The relative intensities are easily calculated also. If you have access to a copy of Cullity's Elements of X-Ray Diffraction, look at Chapter 4, section 13 and Table 4-2.

Calculated the same from the book you suggested. However i need it for the comparison of experimental data with the theory and other literature.

FYI - the "JCPDS" or Joint Committee on Powder Diffraction Standards is old nomenclature. The Powder Diffraction File is maintained today (since 1978) by the International Center for Diffraction Data (http://www.icdd.com/profile/history.htm) and consists of several databases including the NBS/NIST file, the Linus Pauling file, the ICSD, the Cambridge Structure Database (CSD), in addition to the original (and updated annually) PDF database.

There will be a very large number of entries for fcc Fe. There are 47 entries for fcc-Fe in the Inorganic Crystal Structure Database alone. Even if you restrict to room temperature and normal pressure there are many entries - all pretty much the same of course and probably identical to your calculations if you have done them right.

Also you should look at the COD (www.crystallography.net) which is a free database - I just ran a search and found many entries for fcc-Fe.

.. in any case I still don't understand why you need it. To compare "experimental data with theory" you just need some full pattern fitting or modelling tool.

I guess I might say that the Rietveld method and the Whole Powder Pattern Modelling are the two state of the art techniques for structure and microstructure refinement (i.e. extraction of the most sound, from a mathematical point of view, model parameters).

I agree with Edward Payzent completely

Nilesh! "for the comparison of experimental data with the theory", it is my opinion that you may need to simulate such "theoretical profile" using for example the Bruker LEPTOS software (or similar) and the lattice parameters as indicated by Matteo and Edward Andrew. Matteo's WPPM would be the most complete technique for the case of a conventional linear equatorial diffractogram.

Here are some examples of theoretical Bragg profiles developed with LEPTOS and kindly provided to assist us by Dr. Wayne Lin of Bruker. As you can see the theoretical profiles for GaAs (004) for example have many shapes depending on optics and beam conditioners used. Please note that the "asymmetry" of the profile switches sides depending on the optics used as well. Their shapes are distinctly different.

GaAs (004) Theoretical and Experimental data compared using identical optics and beam conditioners: http://www.flickr.com/photos/85210325@N04/9430820747/in/set-72157635172219571

By quantifying the deviation from the "theoretical profile" we are potentially able to infer the "stacking fault" density as well as the character of the missing rows (Ga or As) depending on if the "deviation" was on the high angle or low angle side for each VOXEL of real space on the sample.