Category: atom_site_displace_Fourier_param
Data type: numb (with optional s.u. in parentheses)
Must appear in a looped list containing '_atom_site_displace_Fourier_param_id'
Enumeration range: -1.0 -> 1.0
Enumeration default: 0.0
Units: cy ( Cycles)
The displacive distortion of a given atom or rigid group (see also _atom_site_rot_Fourier_param_phase) is usually parameterized by Fourier series. Each term of the series commonly adopts two different representations: the sine-cosine form, Ac cos(2\p k r)+As sin(2\p k r); and the modulus-argument form, |A| cos(2\p k r+\f); where k is the wave vector of the term and r is the atomic average position. _atom_site_displace_Fourier_param_phase is the phase (\f) in cycles of the complex amplitude corresponding to the Fourier term defined by _atom_site_displace_Fourier_atom_site_label, _atom_site_displace_Fourier_axis, and _atom_site_displace_Fourier_wave_vector_seq_id.