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International
Tables for Crystallography Volume G Definition and exchange of crystallographic data Edited by J. R. Hester and B. McMahon © International Union of Crystallography 2026 |
International Tables for Crystallography (2026). Vol. G. Early view chapter
https://doi.org/10.1107/97809553602060001011 Chapter 4.2 Core dictionary (coreCIF) |
Core dictionary version 3.3.0
_refine_ls.R_I_factor
Name:_refine_ls.R_I_factor
Aliases:
_refine_ls_R_I_factor
_refine.ls_R_I_factor_obs
Definition:
Residual factor R(I) for significantly intense reflections (satisfying
_reflns.threshold_expression) and included in the refinement. This is
most often calculated in Rietveld refinements of powder data, where it
is referred to as R~B~ or R~Bragg~.
sum | I(meas_gt) - I(calc) |
R(I) = -----------------------------
sum | I(meas_gt) |
I(meas_gt) = the net 'observed' intensities
I(calc) = the net calculated intensities
and the sum is taken over the specified reflections.
Type: Real
Units: none
The permitted range is 0.0 → infinity
Category:
refine_ls
