Definition:
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/2\p) 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.
Appears in list containing _atom_site_displace_Fourier_param_id
The permitted range is -1.0 -> 1.0
Enumeration default: 0.0
Type: numb
Category: atom_site_displace_Fourier_param
Copyright © 2005 International Union of Crystallography