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Item _refine.overall_FOM_work_R_set
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Description
Average figure of merit of phases of reflections included in
the refinement.
This value is derived from the likelihood function.
FOM = I_1(X)/I_0(X)
I_0, I_1 = zero- and first-order modified Bessel function
of the first kind
X = sigma_A |E_o| |E_c|/SIGMA
E_o, E_c = normalized observed and calculated structure
factors
sigma_A = SQRT(Sigma_P/Sigma_N)
estimated using maximum likelihood
Sigma_P = sum_{atoms in model} f^2
Sigma_N = sum_{atoms in crystal} f^2
f = is form factor of atoms
delta_x = expected error
SIGMA = (sigma_{E;exp})^2 + epsilon (1-{sigma_A)^2)
sigma_{E;exp} = uncertainties of normalized observed
structure factors
epsilon = multiplicity of diffracting plane
Ref: (sigma_A estimation) "Refinement of Macromolecular
Structures by the Maximum-Likelihood Method",
Murshudov, G. N., Vagin A. A. & Dodson, E. J. (1997).
Acta Cryst. D53, 240-255.
Category
refine
Mandatory Code
no
Data Type Code
float
Alias Names
Alias Name |
Dictionary |
Version |
_refine.ebi_overall_FOM_work_Rset |
ebi_extensions |
1.0 |
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