2. Crystal Structure

diffraction pattern for cubic unit cellad hkl = ——————√h 2 + k 2 + l 2and λ = 2d sinθ2 a sinθλ = ———————√h 2 + k 2 + l 2rules for determining the diffracting {hkl}planes in cubic crystalsreflection present reflection absentBCC (h + k + l) = even (h + k + l) = oddFCC (h, k, l) all odd orall even(h, k, l) not all oddor all evenex. Diffraction pattern for W sample by theuse of a diffractometer with Cu radiationW : BCC structure21