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edits

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Line 67:
Line 67:
~~ ~~<math>+
−~~ ~~R_{scale}=\frac{\sum_{hkl}\vert F_{hkl,i}-F_{hkl,j}\vert}{0.5\sum_{hkl} F_{hkl,i}+F_{hkl,j}}+
−~~ ~~</math>+
+
~~ ~~<math>+
−~~ ~~R=\frac{\sum_{hkl}\vert F_{hkl}^{obs}-F_{hkl}^{calc}\vert}{\sum_{hkl} F_{hkl}^{obs}}+
−~~ ~~</math>+
+

=== Comparing two sets of structure factor amplitudes or intensities ===

=== Comparing two sets of structure factor amplitudes or intensities ===

The following is symmetric, and suitable for comparing two data sets, or two model amplitudes:

The following is symmetric, and suitable for comparing two data sets, or two model amplitudes:

−: <math>

+R_{scale}=\frac{\sum_{hkl}\vert F_{hkl,i}-F_{hkl,j}\vert}{0.5\sum_{hkl} F_{hkl,i}+F_{hkl,j}}

+</math>

+for amplitudes, and analogously for intensities.

for amplitudes, and analogously for intensities.

=== Model quality indicators ===

=== Model quality indicators ===

* R and [[iucr:Free_R_factor|R<sub>free</sub>]] : the formula for both is

* R and [[iucr:Free_R_factor|R<sub>free</sub>]] : the formula for both is

−: <math>

+R=\frac{\sum_{hkl}\vert F_{hkl}^{obs}-F_{hkl}^{calc}\vert}{\sum_{hkl} F_{hkl}^{obs}}

+</math>

+where <math>F_{hkl}^{obs}</math> and <math>F_{hkl}^{calc}</math> have to be scaled w.r.t. each other. R and R<sub>free</sub> differ in the set of reflections they are calculated from: R is calculated for the [[working set]], whereas R<sub>free</sub> is calculated for the [[test set]].

where <math>F_{hkl}^{obs}</math> and <math>F_{hkl}^{calc}</math> have to be scaled w.r.t. each other. R and R<sub>free</sub> differ in the set of reflections they are calculated from: R is calculated for the [[working set]], whereas R<sub>free</sub> is calculated for the [[test set]].

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