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for a beam can be calculated as the sum of the products of pairs of structure factors whose indices sum to the desired values of
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who introduced it in 1952, is a mathematical relationship that allows one to calculate probable values for the
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indicates the sign of the structure factor (positive if the phase is 0 and negative if it is
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that the relationship is true, which becomes higher the stronger the beams are.
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254:{\displaystyle F_{hkl}=\sum _{h'k'l'}F_{h'k'l'}F_{h-h',k-k',l-l'}}
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and the Sayre equation reduces to the triplet relationship:
479:"The squaring method: A new method for phase determination"
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to solve a structure. Its formulation is the following:
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of some diffracted beams. It is used when employing
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387:{\displaystyle S_{h}\approx S_{h'}S_{h-h'}}
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74:Learn how and when to remove this message
306:structure, the phases can only be 0 or
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514:Crystal Structure Determination
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516:. Springer. p. 102.
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449:{\displaystyle \approx }
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458:probability
96:David Sayre
56:introducing
531:3540206442
464:References
436:) and the
396:where the
491:: 60–65.
444:≈
424:π
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136:∑
546:Category
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