1. The problem statement, all variables and given/known data I am trying to calculate the atomic form factor for various crystals (NaCl, LiF, GaP, Si) in an x-ray diffraction experiment. There seems to be very little information on this topic anywhere. 2. Relevant equations I understand how to derive the geometric form factor Sk = sum of exp[i.pi.K.r] And the atomic form factor is Sk = ∑exp[i.pi.K.r].fj Where fj(K) = -1/e ∫dr exp[i.K.r].pj(r) 3. The attempt at a solution For a BCC lattice Sk = 1+(-1)^n1+n2+n3 -monatomic My guess is that I sub in Sk = f1(1) + f2(-1)^n1+n2+n3 I am not sure if this is correct and how I can generalize it, any help would be appreciated. Thanks.