Need help getting the calibration curve of diffractometer

[chicko1290]

I have obtained an XRD pattern for Silicon, with the peaks occurring at 28.5, 47.35, 56.15, 69.3,76.4,88.05 degrees within the 2theta range.

h k l d-space
1 1 1 3.1200
2 2 0 1.9100
3 1 1 1.6300
4 0 0 1.3500
3 3 1 1.2400
4 2 2 1.1000

these are the values from the ICDD that are given. I have to construct a calibration curve for the diffractometer, which is meant to be a graph of the 2theta value vs. the correction angle. Except I have no idea how to calculate the correction angle

I assume I have to use Bragg's Law and the lattice parameter
1/d^2 = (h^2 + k^2 + l^2)/a^2

Please help as I can only find the value of a, then don't know what too do. Please help.

 

[litup]

Don't know if this helps but found this international data base:
http://en.wikipedia.org/wiki/International_Centre_for_Diffraction_Data