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Crystallography and Diffraction Techniques. Myoglobin. Types of diffraction. X-ray diffraction Electron diffraction Neutron diffraction. Myoglobin diffraction pattern 1962 Nobel Prize by Max Perutz and Sir John Cowdery Kendrew.
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Types of diffraction • X-ray diffraction • Electron diffraction • Neutron diffraction Myoglobin diffraction pattern 1962 Nobel Prize by Max Perutz and Sir John Cowdery Kendrew Enhanced visibility of hydrogen atoms by neutron crystallography on fully deuterated myoglobin
1 A About 1 Å
Wave of electrons The electrons are accelerated in an electric potential U to the desired velocity:
From real lattice to reciprocal lattice Real holes Reflection pattern Crystal lattice is a real lattice, while its reflection pattern is its corresponding reciprocal lattice.
TEM image of Si? or Diamond? • Real lattice viewed from (110) direction. Si Diamond
Ewald Sphere and Diffraction Pattern Paul Peter Ewald (1888~1985) • The Ewald sphere is a geometric construct used in X-ray crystallography which neatly demonstrates the relationship between: • the wavelength of the incident and diffracted x-ray beams, • the diffraction angle for a given reflection, • the reciprocal lattice of the crystal