Index

Modulated and composite structures dictionary (msCIF) version 1.0.1

_atom_site_rot_Fourier_param_cos

Definition:

   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_cos is the cosine
   coefficient (Rc) in degrees 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
Enumeration default: 0.0

Type: numb

Category: atom_site_rot_Fourier_param