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Introduction to diffraction |
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1 | (8) |
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1 | (1) |
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X-ray scattering from electrons |
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1 | (1) |
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X-ray scattering from atoms |
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1 | (1) |
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X-ray scattering from a unit cell |
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2 | (1) |
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The effects of the crystal lattice |
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2 | (1) |
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X-ray scattering from the crystal |
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3 | (1) |
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The structure-factor equation |
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4 | (1) |
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The electron-density equation |
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5 | (1) |
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A mathematical relationship |
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6 | (1) |
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6 | (1) |
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7 | (1) |
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8 | (1) |
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Introduction to symmetry and diffraction |
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9 | (18) |
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The relationship between a crystal structure and its diffraction pattern |
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9 | (1) |
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Translation symmetry in crystalline solids |
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10 | (2) |
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Symmetry of individual molecules, with relevance to crystalline solids |
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12 | (4) |
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Symmetry in the solid state |
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16 | (2) |
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18 | (2) |
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20 | (7) |
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24 | (3) |
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Crystal growth and evaluation |
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27 | (14) |
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27 | (1) |
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27 | (1) |
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28 | (1) |
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28 | (7) |
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28 | (5) |
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33 | (1) |
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33 | (1) |
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34 | (1) |
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34 | (1) |
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35 | (1) |
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35 | (1) |
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36 | (1) |
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36 | (1) |
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36 | (5) |
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36 | (2) |
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38 | (1) |
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39 | (2) |
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Space-group determination |
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41 | (12) |
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41 | (1) |
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Prior knowledge and information other than from diffraction |
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42 | (1) |
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Metric symmetry and Laue symmetry |
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43 | (1) |
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43 | (1) |
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44 | (3) |
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The statistical distribution of intensities |
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47 | (1) |
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48 | (2) |
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A brief conducted tour of some entries in International Tables for Crystallography, Volume A |
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50 | (3) |
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52 | (1) |
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Background theory for data collection |
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53 | (20) |
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53 | (1) |
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A step-wise theoretical journey through an experiment |
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53 | (2) |
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The geometry of X-ray diffraction |
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55 | (3) |
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Real-space considerations: Bragg's law |
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55 | (1) |
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Reciprocal-space considerations: the Ewald sphere |
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56 | (2) |
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Determining the unit cell: the indexing process |
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58 | (4) |
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Indexing: a conceptual view |
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58 | (2) |
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60 | (2) |
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Relating diffractometer angles to unit cell parameters: determination of the orientation matrix |
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62 | (2) |
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Data-collection procedures and strategies |
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64 | (3) |
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Criteria for selecting which data to collect |
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64 | (1) |
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How best to measure data: the need for reflection scans |
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65 | (2) |
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Extracting data intensities: data integration and reduction |
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67 | (6) |
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67 | (1) |
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68 | (1) |
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Crystal and geometric corrections to data |
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68 | (4) |
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72 | (1) |
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Practical aspects of data collection |
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73 | (20) |
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73 | (1) |
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Collecting data with area-detector diffractometers |
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73 | (2) |
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75 | (2) |
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75 | (1) |
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76 | (1) |
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77 | (1) |
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77 | (1) |
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77 | (3) |
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Multiwire proportional chamber (MWPC) |
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77 | (1) |
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Phosphor coupled to a TV camera |
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78 | (1) |
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78 | (1) |
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Charge-coupled device (CCD) |
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78 | (2) |
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Some characteristics of CCD area-detector systems |
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80 | (2) |
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81 | (1) |
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Non-uniform intensity response |
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81 | (1) |
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81 | (1) |
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81 | (1) |
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82 | (6) |
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Unit cell and orientation matrix determination |
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84 | (2) |
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86 | (1) |
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Re-harvest the reflections |
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86 | (1) |
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87 | (1) |
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87 | (1) |
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87 | (1) |
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88 | (1) |
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88 | (5) |
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88 | (1) |
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89 | (1) |
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89 | (1) |
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90 | (1) |
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91 | (2) |
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Practical aspects of data processing |
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93 | (10) |
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Data reduction and correction |
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93 | (1) |
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Integration input and output |
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93 | (1) |
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94 | (1) |
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95 | (1) |
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95 | (1) |
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Examples of more problematic cases |
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96 | (2) |
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Twinning and area-detector data |
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98 | (1) |
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Some other special cases (in brief) |
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99 | (4) |
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101 | (2) |
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103 | (14) |
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103 | (1) |
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Forward and reverse Fourier transforms |
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104 | (3) |
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Some mathematical and computing considerations |
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107 | (1) |
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Uses of different kinds of Fourier syntheses |
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108 | (4) |
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109 | (1) |
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109 | (1) |
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Full electron-density maps, using (8.2) or (8.3) as they stand |
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109 | (1) |
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110 | (1) |
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111 | (1) |
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Other uses of difference syntheses |
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112 | (1) |
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Weights in Fourier syntheses |
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112 | (1) |
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Illustration in one dimension |
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113 | (4) |
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114 | (1) |
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Fo synthesis, as used in developing a partial structure solution |
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114 | (1) |
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114 | (1) |
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114 | (1) |
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115 | (2) |
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Patterson syntheses for structure determination |
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117 | (16) |
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117 | (1) |
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What the Patterson synthesis means |
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118 | (3) |
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Finding heavy atoms from a Patterson map |
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121 | (5) |
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One heavy atom in the asymmetric unit of P1 |
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121 | (1) |
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One heavy atom in the asymmetric unit of P21/c |
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122 | (2) |
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One heavy atom in the asymmetric unit of P212121 |
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124 | (1) |
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One heavy atom in the asymmetric unit of Pbca |
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124 | (1) |
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One heavy atom in the asymmetric unit of P21 |
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125 | (1) |
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Two heavy atoms in the asymmetric unit of P1 and other space groups |
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125 | (1) |
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Patterson syntheses giving more than one possible solution, and other problems |
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126 | (2) |
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128 | (5) |
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129 | (1) |
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129 | (2) |
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131 | (2) |
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Direct methods of crystal-structure determination |
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133 | (16) |
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133 | (1) |
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The physical basis of direct methods |
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134 | (1) |
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Constraints on the electron density |
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135 | (4) |
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135 | (1) |
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Non-negative electron density |
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136 | (1) |
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Random atomic distribution |
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137 | (2) |
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Maximum value of ι p3 (x)dV |
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139 | (1) |
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139 | (1) |
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140 | (1) |
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Equal molecules and p(x) = const. |
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140 | (1) |
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140 | (1) |
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141 | (1) |
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142 | (1) |
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Setting up phase relationships |
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142 | (1) |
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Finding reflections for phase determination |
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142 | (2) |
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Assignment of starting phases |
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144 | (1) |
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Phase determination and refinement |
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144 | (1) |
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144 | (1) |
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145 | (1) |
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Completion of the structure |
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146 | (3) |
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147 | (2) |
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An introduction to maximum entropy |
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149 | (6) |
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149 | (1) |
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150 | (3) |
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Calculations with incomplete data |
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150 | (2) |
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152 | (1) |
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152 | (1) |
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153 | (2) |
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Least-squares fitting of parameters |
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155 | (14) |
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155 | (1) |
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156 | (6) |
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Variances and covariances |
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158 | (1) |
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158 | (2) |
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160 | (2) |
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162 | (2) |
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164 | (1) |
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165 | (4) |
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167 | (2) |
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Refinement of crystal structures |
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169 | (20) |
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169 | (3) |
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170 | (1) |
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Structure factors from the continuous electron density |
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170 | (1) |
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Electron density from the structure amplitude and phase |
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170 | (2) |
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Structure factor from a parameterized model |
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172 | (1) |
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Reasons for performing refinement |
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172 | (3) |
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To improve phasing so that computed electron density maps more closely represent the actual electron density |
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172 | (1) |
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To try to verify that the structure is `correct' |
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173 | (2) |
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To obtain the `best' values for the parameters in the model |
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175 | (1) |
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Data quality and limitations |
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175 | (2) |
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175 | (1) |
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176 | (1) |
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176 | (1) |
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Weak reflections and systematic absences |
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176 | (1) |
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177 | (1) |
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177 | (1) |
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177 | (3) |
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178 | (1) |
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178 | (1) |
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179 | (1) |
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180 | (1) |
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180 | (2) |
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Under- and over-parameterization |
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182 | (1) |
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182 | (1) |
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183 | (1) |
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Pseudo-symmetry, wrong space groups and Z' 1 structures |
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183 | (1) |
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184 | (5) |
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186 | (3) |
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Analysis of extended inorganic structures |
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189 | (16) |
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189 | (1) |
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190 | (4) |
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191 | (1) |
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192 | (1) |
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Limits of Bragg diffraction |
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193 | (1) |
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194 | (1) |
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195 | (1) |
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Case history 1 - BiMg2VO6 |
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196 | (3) |
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Case history 2 - Mo2P4O15 |
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199 | (6) |
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203 | (2) |
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The derivation of results |
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205 | (16) |
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205 | (1) |
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205 | (6) |
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Fractional and Cartesian co-ordinates |
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205 | (2) |
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Bond distance and angle calculations |
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207 | (1) |
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208 | (1) |
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Transforming co-ordinates |
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208 | (1) |
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209 | (2) |
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Assessing significant differences |
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211 | (1) |
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Least-squares planes and dihedral angles |
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211 | (2) |
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Conformation of rings and other molecular features |
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213 | (1) |
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Hydrogen atoms and hydrogen bonding |
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213 | (1) |
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214 | (7) |
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215 | (1) |
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`The equivalent isotropic displacement parameter' |
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215 | (1) |
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Symmetry and anisotropic displacement parameters |
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216 | (1) |
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Models of thermal motion and geometrical corrections: rigid-body motion |
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217 | (1) |
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Atomic displacement parameters and temperature |
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218 | (1) |
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219 | (2) |
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Random and systematic errors |
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221 | (30) |
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Random and systematic errors |
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221 | (1) |
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Random errors and distributions |
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222 | (7) |
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222 | (1) |
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222 | (3) |
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Theoretical distributions |
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225 | (2) |
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227 | (2) |
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The standard error on the mean |
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229 | (1) |
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229 | (3) |
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Testing for normality using a histogram |
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230 | (1) |
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The X2 test for normality |
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231 | (1) |
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Averaging data when X2red»1 |
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232 | (1) |
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232 | (6) |
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Weights used in least-squares refinement with single-crystal diffraction data |
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233 | (1) |
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Robust-resistant weighting schemes and outliers |
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234 | (1) |
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Assessing weighting schemes |
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235 | (3) |
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Analysis of the agreement between observed and calculated data |
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238 | (2) |
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238 | (1) |
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239 | (1) |
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Estimated standard deviations and standard uncertainties of structural parameters |
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240 | (2) |
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Correlation and covariance |
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240 | (2) |
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242 | (1) |
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242 | (9) |
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Systematic errors in the data |
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243 | (1) |
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244 | (1) |
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Errors and limitations of the model |
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244 | (3) |
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Assessment of a structure determination |
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247 | (3) |
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250 | (1) |
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251 | (20) |
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Introduction to powder diffraction |
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251 | (1) |
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Powder versus single-crystal diffraction |
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252 | (2) |
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254 | (4) |
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Information contained in a powder pattern |
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258 | (3) |
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258 | (1) |
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259 | (1) |
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260 | (1) |
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261 | (1) |
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261 | (3) |
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Structure solution from powder diffraction data |
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264 | (1) |
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265 | (6) |
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268 | (3) |
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271 | (28) |
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271 | (1) |
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A simple model for twinning |
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271 | (1) |
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272 | (2) |
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Diffraction patterns from twinned crystals |
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274 | (2) |
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Inversion, merohedral and pseudo-merohedral twins |
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276 | (3) |
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279 | (1) |
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280 | (2) |
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The derivation of non-merohedral twin laws |
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282 | (1) |
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283 | (2) |
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285 | (14) |
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296 | (3) |
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The presentation of results |
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299 | (20) |
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299 | (1) |
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300 | (1) |
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300 | (1) |
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301 | (1) |
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302 | (4) |
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Creating three-dimensional illusions |
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306 | (1) |
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307 | (1) |
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Textual information in drawings |
|
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307 | (1) |
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Some hints for effective drawings |
|
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308 | (1) |
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309 | (1) |
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310 | (2) |
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310 | (1) |
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311 | (1) |
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311 | (1) |
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312 | (1) |
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312 | (3) |
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312 | (1) |
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313 | (1) |
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313 | (1) |
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313 | (1) |
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314 | (1) |
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|
315 | (4) |
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The crystallographic information file (CIF) |
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319 | (8) |
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319 | (1) |
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|
319 | (2) |
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|
321 | (1) |
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Some properties of the CIF format |
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321 | (2) |
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323 | (4) |
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323 | (1) |
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324 | (1) |
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|
325 | (2) |
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Crystallographic databases |
|
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327 | (6) |
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|
327 | (1) |
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What types of search are possible? |
|
|
327 | (1) |
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What information can you get out? |
|
|
328 | (1) |
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What can you use databases for? |
|
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328 | (1) |
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What are the limitations? |
|
|
328 | (1) |
|
Short descriptions of crystallographic databases |
|
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328 | (5) |
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X-ray and neutron sources |
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333 | (10) |
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|
333 | (1) |
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|
333 | (2) |
|
Synchrotron X-ray sources |
|
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335 | (4) |
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|
339 | (4) |
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Appendix A: Useful mathematics and formulae |
|
|
343 | (10) |
|
|
343 | (1) |
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|
343 | (1) |
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|
344 | (1) |
|
Waves and structure factors |
|
|
345 | (1) |
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|
346 | (2) |
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|
348 | (1) |
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|
348 | (1) |
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|
349 | (1) |
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|
350 | (1) |
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|
351 | (2) |
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Appendix B: Questions and answers |
|
|
353 | (32) |
Index |
|
385 | |