Data Item _refine.overall_SU_R_Cruickshank_DPI
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General 
- Item name
- _refine.overall_SU_R_Cruickshank_DPI
- Category name
- refine
- Attribute name
- overall_SU_R_Cruickshank_DPI
- Required in PDB entries
- no
- Used in current PDB entries
- Yes, in about 6.0 % of entries
Item Description
The overall standard uncertainty (e.s.d.) of the thermal
parameters based on the crystallographic R value, expressed
in a formalism known as the dispersion precision indicator
(DPI).
The overall standard uncertainty (sigmaB) gives an idea
of the uncertainty in the B values of averagely defined
atoms (atoms with B values equal to the average B value).
N_a
(sigma_B)2 = 0.65 --------- (R_value)2 (D_min)2 C(-2/3)
(N_o-N_p)
N_a = number of atoms
N_o = number of reflections included in refinement
N_p = number of refined parameters
R_value = conventional crystallographic R-value
D_min = maximum resolution
C = completeness of data
Ref: Cruickshank, D. W. (1997). "Refinement of macromolecular
structures". Proc. CCP4 study weekend.
"Simplified error estimation a la Cruickshank in
macromolecular crystallography", Murshudov G. N. &
Dodson E. J. (1997). CCP4 Newsletter, no. 33.
http://www.dl.ac.uk/CCP/CCP4/newsletter33/
Data Type 
- Data type code
- float
- Data type detail
- int 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]+)?
Aliases
| Alias Item Name | Dictionary Name | Dictionary Version |
|---|---|---|
| _refine.ebi_Overall_ESU_R_Cruickshanks_DPI | ebi_extensions | 1.0 |