Data Collection and Data Reduction Techniques for ... - Bruker

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The q-vector concept These spots are regularly distributed <strong>and</strong> they can be indexed if one or more additional vectors are added to the reciprocal basis. The general diffraction spot at Q can be expressed as where the vector q is called the modulation vector. Reflections having index m equal to zero are the main reflections, the others are satellite reflections. The modulation vector q can be expressed in the reciprocal basis: q a * * * 1 a 2 a 3 2/27/2013 20
Types of Modulated Structures Commensurate cases If the superspots are located at simple fractions of the vectors of the reciprocal lattice of the substructure, e.g., at q=(½,0,0), the resulting broken symmetry is a doubling of the unit cell along the a axis. Such a modulation is called a commensurate superstructure. Incommensurate cases In some materials, superspots will occur at positions that do not represent a simple fraction, say q=(0.5234,0,0). In such a case a structure results that strictly speaking has lost all translational symmetry in a particular direction. This is called an incommensurate structure. 2/27/2013 21
Page 1 and 2: Data Collection and Data Reduction
Page 3 and 4: Dr. Charles Campana - Senior Applic
Page 5 and 6: Pseudoephedrine Hydrochloride in th
Page 7 and 8: Pseudoephedrine at Low Temperature
Page 9 and 10: Diffraction pattern at varying temp
Page 11 and 12: A closer look at how the satellites
Page 13 and 14: How to better describe the structur
Page 15 and 16: Two-dimensional periodic arrangemen
Page 17 and 18: Two-dimensional periodic arrangemen
Page 19: Defining the modulation vector q -
Page 23 and 24: Identifying the main lattice (1)
Page 25 and 26: Identifying the main lattice (3)
Page 27 and 28: Indexing the main lattice • Defin
Page 29 and 30: Defining the satellites - q vector
Page 31 and 32: Data integration • The q-vector i
Page 33 and 34: Structure refinement in Jana 2006
Page 35 and 36: Collection of Modulated Structure D
Page 37 and 38: Harvest Reflections • Reflections
Page 39 and 40: Refinement of the initial unit cell
Page 41 and 42: Refinement of the I-centered orthor
Page 43 and 44: RLATT view of the I-centered unit c
Page 45 and 46: Integration of data with one q-vect
Page 47 and 48: Format of JANA2006-compatible .hk6
Page 49 and 50: Pseudo precession image - h1l 2/27/
Page 55 and 56: Structure refinement The structure
Page 57 and 58: Animated conformation changes • C
Page 59: Jana2006 Tutorial 2/27/2013 59
Page 62 and 63: Importing of Bruker data into Jana2
Page 68: Importing of Bruker data into Jana2

Data Collection and Data Reduction Techniques for ... - Bruker

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