# Core CIF Dictionary version 2.3

# _diffrn_reflns_class_[]

### Name

`'_diffrn_reflns_class_[]'`
**Category:** category_overview

**Data type:** null

**Examples:**

loop_
_diffrn_reflns_class_number
_diffrn_reflns_class_d_res_high
_diffrn_reflns_class_d_res_low
_diffrn_reflns_class_av_R_eq
_diffrn_reflns_class_code
_diffrn_reflns_class_description
1580 0.551 6.136 0.015 'Main' 'm=0; main reflections'
1045 0.551 6.136 0.010 'Sat1' 'm=1; first-order satellites'

Example 1 - example corresponding to the one-dimensional incommensurately
modulated structure of K~2~SeO~4~. Each reflection class is
defined by the number m=sum|m~i~|, where the m~i~ are the
integer coefficients that, in addition to h,k,l, index the
corresponding diffraction vector in the basis defined for
the reciprocal lattice.

### Definition

Data items in the DIFFRN_REFLNS_CLASS category record details
about the classes of reflections measured in the diffraction
experiment.

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