International
Tables for
Crystallography
Volume F
Crystallography of biological macromolecules
Edited by M. G. Rossmann and E. Arnold

© International Union of Crystallography 2006
International Tables for Crystallography (2006). Vol. F. ch. 25.2, p. 697

Section 25.2.1.3.2. Global anisotropic scaling

W. Fureya*

25.2.1.3.2. Global anisotropic scaling

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With this option, applied after relative Wilson scaling, the unique parameters of a symmetric 3 × 3 scaling tensor S are determined by two cycles of least-squares minimization of [\textstyle\sum\limits_{hkl}\displaystyle W_{hkl} (F_{P} - SF_{PH})^{2} \eqno(25.2.1.3)] with respect to S, where [W_{hkl}] is a weighting factor, [{S = S_{11} O_{x}^{2} + S_{22} O_{y}^{2} + S_{33} O_{z}^{2} + 2(S_{12} O_{x} O_{y} + S_{13} O_{x} O_{z} + S_{23} O_{y} O_{z})} \eqno(25.2.1.4)] and [O_{x}], [O_{y}], [O_{z}] are direction cosines of the reciprocal-lattice vector expressed in an orthogonal system. The derivative data are then placed on the scale of the native by multiplying each derivative amplitude by the appropriate S.








































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