Modulated and composite structures dictionary (msCIF) version 1.0.1
The code that identifies an atom or rigid group in a loop in which the parameters of the special function that describes its occupational modulation are listed. This code must match the _atom_site_label of the associated coordinate list and conform to the rules described in _atom_site_label.
Appears in list as essential element of loop structure
Must match data name_atom_site_label