XmlmmCIF equivalent: diffrn_standards Data items in the DIFFRN_STANDARDS category record details about the set of standard reflections used to monitor intensity stability during measurement of diffraction intensities. Note that these records describe properties common to the set of standard reflections, not the standard reflections themselves. XmlmmCIF equivalent: diffrn_standards/decay_ The percentage decrease in the mean of the intensities for the set of standard reflections 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. XmlmmCIF equivalent: diffrn_standards/interval_count The number of reflection intensities between the measurement of standard reflection intensities. XmlmmCIF equivalent: diffrn_standards/interval_time The time in minutes between the measurement of standard reflection intensities. XmlmmCIF equivalent: diffrn_standards/number The number of unique standard reflections used in the diffraction measurements. XmlmmCIF equivalent: diffrn_standards/scale_sigma The standard uncertainty (e.s.d.) of the individual mean standard scales applied to the intensity data. XmlmmCIF equivalent: diffrn_standards/diffrn_id This data item is a pointer to _diffrn.id in the DIFFRN category.