Modulated Structures CIF Dictionary version 1.0

_atom_site_rot_Fourier_param_[]

Name

Category: category_overview

Data type: null

Examples:

     loop_
         _atom_site_rot_Fourier_param_id
         _atom_site_rot_Fourier_param_cos
         _atom_site_rot_Fourier_param_sin
              SeO4_x_1    -4.2(1)   0.91(3)
              SeO4_y_1     4.3(1)   0.

Example 1 - example corresponding to the one-dimensional incommensurately modulated structure of K~2~SeO~4~. The meaning of _atom_site_rot_Fourier_param_id is given in the examples of the ATOM_SITE_ROT_FOURIER category.

     _atom_sites_rot_Fourier_axes_description
     ;   a1 and a2 are respectively the long molecular axis
         and the axis normal to the mean molecular plane.
     ;
     loop_
         _atom_site_rot_Fourier_param_id
         _atom_site_rot_Fourier_param_modulus
         _atom_site_rot_Fourier_param_phase
              Ph1_a1_1  11.0(2)  0.
              Ph2_a1_1  11.0(2)  0.5
              Bph_a2_1   1.0(1)  0.25

Example 2 - extracted from Baudour & Sanquer [(1983). Acta Cryst. B39, 75-84.] Note the entry from the ATOM_SITES_ROT_FOURIER category to describe collective information relating to all the atom sites. The meaning of _atom_site_rot_Fourier_param_id is given in the examples of the ATOM_SITE_ROT_FOURIER category.

Definition

    	
   Data items in the ATOM_SITE_ROT_FOURIER_PARAM category record 
   details about the coefficients of the Fourier series used to 
   describe the rotational component of the displacive modulation of
   a given rigid group. The translational part would appear in a
   separate list of items belonging to the
   ATOM_SITE_DISPLACE_FOURIER_PARAM category. The Fourier components
   are defined in the category ATOM_SITE_ROT_FOURIER and are listed 
   separately.