Non-centrosymmetric Space Groups - Practical Electron Microscopy and Database - - An Online Book - |
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Microanalysis | EM Book https://www.globalsino.com/EM/ | ||||||||
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Two centrosymmetric reciprocal lattice points (hkl) and (-h-k-l) are called Friedel (or Bijvoet) pair. Friedel's law describes the relationship between the structure amplitude of the two centrosymmetric reciprocal lattice points. According to the Friedel's law, regardless of whether the crystal structure is centrosymmetric or not, if there is no anomalous scattering the reciprocal space is always centrosymmetric, given by, However, there are still different ways to distinguish if the crystal belongs to centrosymmetric or non-centrosymmetric space groups: Table 1676. Other characteristics of non-centrosymmetric space groups.
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