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Item _refine_analyze.RG_free
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Description
The Hamilton generalized R factor for all reflections that
satisfy the resolution limits established by
_refine_analyze.RG_d_res_high and
_refine_analyze.RG_d_res_low for the free R set of
reflections that were excluded from the refinement.
sum_i sum_j w_{i,j}(|Fobs|_i - G|Fcalc|_i)(|Fobs|_j - G|Fcalc|_j)
Rg = Sqrt( ----------------------------------------------------------------- )
sum_i sum_j w_{i,j} |Fobs|_i |Fobs|_j
where
|Fobs| = the observed structure factor amplitudes
|Fcalc| = the calculated structure factor amplitudes
G = the scale factor which puts |Fcalc| on the
same scale as |Fobs|
w_{i,j} = the weight for the combination of the reflections
i and j.
sum_i and sum_j are taken over the specified reflections
When the covariance of the amplitude of reflection i and
reflection j is zero (i.e. the reflections are independent)
w{i,i} can be redefined as w_i and the nested sums collapsed
into one.
sum_i w_i(|Fobs|_i - G|Fcalc|_i)^2
Rg = Sqrt( ----------------------------------- )
sum_i w_i |Fobs|_i^2
Ref: Hamilton, W. C. (1965). Acta Cryst. 18, 502-510.
Category
refine_analyze
Mandatory Code
no
Data Type Code
float
Enumeration Range
Minimum Value |
Maximum Value |
0.0 |
n.a. |
0.0 |
0.0 |
Alias Names
Alias Name |
Dictionary |
Version |
_refine_analyze.ebi_RG_free |
ebi_extensions |
1.0 |
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Rutgers University, Department of Chemistry
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