Determine the expected diffraction angle for the first-order reflection from the (310) set of planes for bcc chromium when monochromatic radiation of wavelength 0.0777 nm is used. the atomic radius for cr is 0.1249 nm.

In a BCC crystal the distance between two adjacent planes is given by 

For Chromium where  the lattice constant is 

Distance between (310) planes is

The diffraction angle for the n=1 order is


[tex] \theta =25.72 \degree[\tex]