Category: atom_site_U_Fourier
Data type: numb
Must appear in a looped list
containing '_atom_site_U_Fourier_id'
Must match a value of '_atom_site_Fourier_wave_vector_seq_id'
A numeric code identifying the wave vectors of the Fourier terms used to describe the modulation functions corresponding to the temperature factors of an atom or rigid group. This code must match _atom_site_Fourier_wave_vector_seq_id.