# Core CIF Dictionary version 2.3

# _symmetry_equiv_[]

### Name

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

**Data type:** null

**Examples:**

loop_
_symmetry_equiv_pos_as_xyz
+x,+y,+z 1/2-x,-y,1/2+z 1/2+x,1/2-y,-z -x,1/2+y,1/2-z

Example 1 - based on data set TOZ of Willis, Beckwith & Tozer [(1991).
Acta Cryst. C47, 2276-2277].

loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
1 x,y,z
2 1/2-x,-y,1/2+z
3 1/2+x,1/2-y,-z
4 -x,1/2+y,1/2-z

Example 2 - based on data set TOZ of Willis, Beckwith & Tozer [(1991).
Acta Cryst. C47, 2276-2277]. Formally the value of
_symmetry_equiv_pos_site_id can be any unique character string;
it is recommended that it be assigned the sequence number of
the list of equivalent positions for compatibility with
older files in which it did not appear.

### Definition

Data items in the SYMMETRY_EQUIV category list the
symmetry equivalent positions for the space group.

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