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International
Tables for Crystallography Volume G Definition and exchange of crystallographic data Edited by J. R. Hester and B. McMahon © International Union of Crystallography 2026 |
International Tables for Crystallography (2026). Vol. G. Early view chapter
https://doi.org/10.1107/97809553602060001011 Chapter 4.2 Core dictionary (coreCIF) |
Core dictionary version 3.3.0
_diffrn_standards.decay_percent
Name:_diffrn_standards.decay_percent
Aliases:
_diffrn_standards_decay_%
_diffrn_standards.decay_%
_diffrn_standards_decay_percent
Definition:
The percentage decrease in the mean of the intensities for the
standard reflections from the start to the finish of the measurement
process. This value affords a measure of the overall decay in
crystal quality during measurement. Negative values only occur 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%.
Examples:| 0.5(1) | Represents a decay between 0.2% and 0.8%. |
| -1(1) | Change in standards between 2% decay and 4% rise. |
| 0.0(2) | Change in standards between 0.6% decay and 0.6% rise. |
Type: Real
Units: none
The permitted range is -infinity → 100.0
Category:
diffrn_standards
