Crystallographic Information Framework

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Core dictionary (coreCIF) version 2.4.5




   The percentage decrease in the mean
   intensity of the set of standard reflections measured at the
   start of the measurement process and at the finish.  This value
   usually affords a measure of the overall decay in crystal
   quality during the diffraction measurement process.  Negative
   values are used in exceptional instances where the final
   intensities are greater than the initial ones.  If no
   measurable decay has occurred, the standard uncertainty should
   be quoted to indicate the maximum possible value the decay
   might have.  A range of 3 standard uncertainties is considered
   possible.  Thus 0.0(1) would indicate a decay of less than
   0.3% or an enhancement of less than 0.3%.


0.5(1) represents a decay between 0.2% and 0.8%
-1(1) the change in the standards lies between a decay of 2% and an increase of 4%
0.0(2) the change in the standards lies between a decay of 0.6% and an increase of 0.6%.

The permitted range is -infinity -> 100

Type: numb

Category: diffrn_standards