Data Item _refine_analyze.RG_free
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General 
- Item name
- _refine_analyze.RG_free
- Category name
- refine_analyze
- Attribute name
- RG_free
- Required in PDB entries
- no
- Used in currrent PDB entries
- No
Item 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 amplitudes 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.
sum_i w_i(|Fobs|_i - G|Fcalc|_i)2
RG = Sqrt( ----------------------------------- )
sum_i w_i |Fobs|_i2
Ref: Hamilton, W. C. (1965). Acta Cryst. 18, 502-510.
Data Type 
- Data type code
- float
- Data type detail
- float item types are the subset of numbers that are the floating numbers.
- Primitive data type code
- numb
- Regular expression
- -?(([0-9]+)[.]?|([0-9]*[.][0-9]+))([(][0-9]+[)])?([eE][+-]?[0-9]+)?
Allowed Boundary Conditions
| Minimum Value | Maximum Value |
|---|---|
| 0.0 | +∞ |