Definition:
The modulation of the atomic thermal parameters is usually
parameterized by Fourier series. Each term of the series
commonly adopts two different representations: the sine-cosine
form,
U(ij)c cos(2\p k r)+U(ij)s sin(2\p k r),
and the modulus-argument form,
|U(ij)| cos(2\p k r+\c),
where k is the wave vector of the term and r is the atomic
average position. _atom_site_U_Fourier_param_modulus is the
modulus [|U(ij)|], in angstroms squared, of the complex
amplitudes corresponding to the Fourier term defined by
_atom_site_U_Fourier_atom_site_label,
_atom_site_U_Fourier_tens_elem and
_atom_site_U_Fourier_wave_vector_seq_id.
Appears in list containing _atom_site_U_Fourier_param_id
The permitted range is 0.0 -> infinity
Enumeration default: 0.0
Type: numb
Category: atom_site_U_Fourier_param
Copyright © 2005 International Union of Crystallography