Chemistry Reference
In-Depth Information
Protein
Crystallization
Precipitant
Crystal
X-Ray source
Diraction
Detector
Diraction pattern
Computer
Structure Factor
Determination
Structure
FIGURE 3.6
Overview of X-ray crystallography.
R1
Diracted wave
Incident wave
(wavelength λ)
R2
θ
θ
θ
d
Inter-
planar
spacing
θ
θ
d sin θ
d sin θ
FIGURE 3.7
A set of parallel planes with interplanar spacing d produces a diffraction
beam when X-rays R1 and R2 are reflected by the planes at an angle θ. If the difference in
path length, 2(d sin θ), is equal to an integral number (n) of wavelengths, then they construc-
tively interfere with each other. This is Bragg's law of diffraction.
Search WWH ::
Custom Search