Core dictionary (coreCIF) version 2.4.5
An arbitrary identifier that uniquely labels each symmetry operation in the list. In order for the defaults to work correctly, the identity operation should have _space_group_symop_id or _symmetry_equiv_pos_site_id set to 1, and _space_group_symop_operation_xyz or _symmetry_equiv_pos_as_xyz set to x,y,z; i.e. the operation labelled 1 should be the identity operation.
Appears in list as essential element of loop structure
Related item: _symmetry_equiv_pos_site_id (alternate)
Enumeration default: 1