1. The problem statement, all variables and given/known data X rays with wavelength 0.10 nm are incident on a crystal with a hexagonal crystal structure. The x-ray diffraction spectrum is shown in the figure. Figure: What is the atomic spacing D of this crystal? (in nanometers) 2. Relevant equations The Bragg condition: 2*D*cos(theta)=m*lamda where, m=1,2,3... 3. The attempt at a solution (m+1)/(m) ==> cos(50.1)/cos(71.3) = (2/1) (m+1)/(m)==> cos(15.8)/cos(71.3) = (3/1) D=(2*lamda)/(2*cos(theta_2)==> (lamda)/cos(theta_2)==> (0.10nm)/cos(50.1)=0.16nm I just followed a similair example in the book. Maybe I'm getting it wrong because I'm not factoring anything in about the hexagonal shape in my math? *Note: this is a challange problem.