Diffraction-geometry refinement in the DIALS framework

Waterman, D.G.; Winter, G.; Gildea, R.J.; Parkhurst, J.M.; Brewster, A.S.; Sauter, N.K.; Evans, G.

doi:10.1107/S2059798316002187

Figure 1
The diffraction geometry of the simple central impact model used by DIALS. Vectors are expressed in either a reciprocal-space or real-space laboratory frame. The rotation axis $[\hat{\bf e}]$ intersects the origin of laboratory space within the crystal at O_c and defines a right-handed rotation. The direct-beam wavevector s₀ passes through O_c and defines the origin of reciprocal space O_rs at its tip. A reciprocal-lattice point rotated by an angle φ to touch the surface of the Ewald sphere is shown by r_φ. The diffracted beam wavevector s₁ extends from O_c to the tip of r_φ. Further projection of this vector leads to an intersection on a detector plane at the position marked (X, Y). The detector plane is described by three vectors: d₀, which defines the origin of the detector coordinate system O_d at one corner of the plane, and a pair of mutually orthogonal unit vectors $[\hat{\bf d}_x]$ and $[\hat{\bf d}_y]$ defining a Cartesian plane. The detector normal vector $[\hat{\bf d}_n = \hat{\bf d}_x \times \hat{\bf d}_y]$ completes the detector coordinate system basis. The position (X, Y) is recorded if it is inside the pair of limits (x_lim, y_lim).

STRUCTURAL
BIOLOGY

ISSN: 2059-7983

Volume 72| Part 4| April 2016| Pages 558-575

doi:10.1107/S2059798316002187

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