at 5:59 You didn't explain why we can neglect the sine term in the structure factor equation properly. It's important to point out that you can only neglect the sine term here because h+k+l is always an integer for BCC lattices. You seem to have mixed up your unit circle with the Argand diagram. Integers are actually always at 0 radians on your unit circle i.e., i*sin(π*n) = 0. This is explained at the top of p. 122 in the book you cited in the description. The sine term can be neglected for any unit cell for which the trigonometric expansion of the structure factor equation will either have only sine terms that are identically zero, or equal negative sine term for every positive sine term, as is the case for all centrosymmetric space groups, since every (x,y,z) is accompanied by (-x,-y,-z) and sin(-a) = -sin(a), while cos(-a) = cos(a). This is actually quite an important point.
You explained this better in fourteen minutes than my professor did in three hours
Great series on XRD! Many thanks!
So good bro thank you so much
I am watching from india 🇮🇳 ❤
I have my Solid state physics exam tomorrow, you explained it very clear! regards from spain!
Thank you very much! It was so helpful and clear to understand. Keep it up!
Thanks so much, really cool,need to study Debye Waller Factor and it helped a lot,
hope nobody got injured in the background though XD
at 5:59 You didn't explain why we can neglect the sine term in the structure factor equation properly. It's important to point out that you can only neglect the sine term here because h+k+l is always an integer for BCC lattices. You seem to have mixed up your unit circle with the Argand diagram. Integers are actually always at 0 radians on your unit circle i.e., i*sin(π*n) = 0. This is explained at the top of p. 122 in the book you cited in the description. The sine term can be neglected for any unit cell for which the trigonometric expansion of the structure factor equation will either have only sine terms that are identically zero, or equal negative sine term for every positive sine term, as is the case for all centrosymmetric space groups, since every (x,y,z) is accompanied by (-x,-y,-z) and sin(-a) = -sin(a), while cos(-a) = cos(a). This is actually quite an important point.
Simple words hkl are integers hence sine will always be zero
What about the HCP structure factor?
Brilliant
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