Modulated and composite structures dictionary (msCIF) version 1.0.1
The displacive distortion of a given rigid group is not completely described by _atom_site_displace_Fourier_. The rigid rotation of the group around a given axis passing through a fixed point (for example, the centre of mass of the group) is usually parameterized by Fourier series. Each term of the series commonly adopts two different representations: the sine-cosine form, Rc cos(2\p k r)+Rs sin(2\p k r), and the modulus-argument form, |R| cos(2\p k r+\y), where k is the wave vector of the term and r is the atomic average position. _atom_site_rot_Fourier_param_phase is the phase (\y/2\p) in cycles of the complex amplitude corresponding to the Fourier term defined by _atom_site_rot_Fourier_atom_site_label, _atom_site_rot_Fourier_axis and _atom_site_rot_Fourier_wave_vector_seq_id.
Appears in list containing _atom_site_rot_Fourier_param_id
The permitted range is -1.0 -> 1.0
Enumeration default: 0.0