Resolution: Difference between revisions
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The resolution of a diffraction pattern depends on how ordered the crystal is. If it is highly ordered (atoms are in defined positions throughout the crystal and over time), the crystal will diffract to high resolution. The more disorder there is (atoms moving over time, or the content of one unit cell differing from the next), the lower the resolution of the diffraction image. The intensity of diffraction spots drops with increasing disorder. In order to be able to measure weak reflection spots, it is sometimes possible to increase the intensity of the X-rays used in the experiment, increase the exposure time or sensitivity of the detector, or increase the size of the crystals. | The resolution of a diffraction pattern depends on how ordered the crystal is. If it is highly ordered (atoms are in defined positions throughout the crystal and over time), the crystal will diffract to high resolution. The more disorder there is (atoms moving over time, or the content of one unit cell differing from the next), the lower the resolution of the diffraction image. The intensity of diffraction spots drops with increasing disorder. In order to be able to measure weak reflection spots, it is sometimes possible to increase the intensity of the X-rays used in the experiment, increase the exposure time or sensitivity of the detector, or increase the size of the crystals. | ||
The higher the resolution, the more reflections in the data set. The number of reflections increases with the inverse cube of the resolution, so a 1.0 Å data set has eight times the number of reflections than a 2.0 Å data set. | |||
==Electron Density Map vs. Resolution== | ==Electron Density Map vs. Resolution== | ||
