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Category geom_torsion
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Category Description
Data items in the GEOM_TORSION category record details about
molecular and crystal torsion angles, as calculated from the
contents of the ATOM, CELL, and SYMMETRY data.
The vector direction _geom_torsion.atom_site_id_2 to
_geom_torsion.atom_site_id_3 is the viewing direction, and the
torsion angle is the angle of twist required to superimpose the
projection of the vector site2-site1 onto the projection of the
vector site3-site4. Clockwise torsions are positive,
anticlockwise torsions are negative.
Ref: Klyne, W. & Prelog, V. (1960). Experientia, 16, 521-523.
Category Examples
Example 1:
Example 3 - based on data set CLPHO6 of Ferguson, Ruhl, McKervey & Browne
[(1991). Acta Cryst. C48, 2262-2264].
loop_
_geom_torsion.atom_site_id_1
_geom_torsion.atom_site_id_2
_geom_torsion.atom_site_id_3
_geom_torsion.atom_site_id_4
_geom_torsion
_geom_torsion.site_symmetry_1
_geom_torsion.site_symmetry_2
_geom_torsion.site_symmetry_3
_geom_torsion.site_symmetry_4
_geom_torsion.publ_flag
C(9) O(2) C(7) C(2) 71.8(2) . . . . yes
C(7) O(2) C(9) C(10) -168.0(3) . . . 2_666 yes
C(10) O(3) C(8) C(6) -167.7(3) . . . . yes
C(8) O(3) C(10) C(9) -69.7(2) . . . 2_666 yes
O(1) C(1) C(2) C(3) -179.5(4) . . . . no
O(1) C(1) C(2) C(7) -0.6(1) . . . . no
Key Category Items
Items in Category geom_torsion
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