R-factors

Historically, R-factors were introduced by ...

Definitions

Data quality indicators

• R_sym and R_merge: the formula is (someone with LaTex knowledge please don't hesitate to fill in the formula!)
• Redundancy-independant version of the above: R_meas
• measuring quality of averaged intensities/amplitudes: R_p.i.m./R_mrgd-F

Model quality indicators

• R and R_free: the formula is (LaTex please )

what do R-factors try to measure, and how to interpret their values?

• relative deviation of
• typical values: ...

what kind of problems exist with these indicators?

- (R_sym/R_merge) should not be used, R_meas should be used instead (explain why ?)

- R/R_free and NCS: reflections in work and test set are not independant