Gold has a face centered cubic crystal structure, where there are four atoms per unit cell.
Below is a calculated XRD powder pattern for bulk gold. The y-axis caption (not listed) is diffraction intensity in arbitrary units.
Using the Bragg equation, and the fact that Cu Ka radiation was used (λ = 1.541 Å) to calculate this pattern, determine the d-spacing (Å), to 3 decimal places, for the (111) reflection (2θ = 38.184o) and the (222) reflection (at 2θ = 81.732o). These two reflections are related. Which d-spacing is larger and why?