Dear ALL

when you start you refinment in phenix with ***.sca file, fraction of reflection in test set will be created. under options (bottom) in phenix refine, you could see that fraction of reflection in test set is 0.1 which means 10 %

by looking to the PDB header for completely different structures (below) you will find different percentage but always FREE R VALUE TEST SET COUNT is around 3800. so it always take the same 3800 count regardless the number of reflections.

when you look in generated mtz file after the refinment, you see under R-free-flags(+) and R-free-flags(-)  either 0 or 1. what does 0 or 1 mean?

thank you in advance for explaination.

TKDawoD

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REMARK   3   NUMBER OF REFLECTIONS             : 47312     

REMARK   3   NUMBER OF REFLECTIONS (NON-ANOMALOUS) : 24389     

REMARK   3  

REMARK   3  FIT TO DATA USED IN REFINEMENT.

REMARK   3   R VALUE     (WORKING + TEST SET) : 0.1673

REMARK   3   R VALUE            (WORKING SET) : 0.1636

REMARK   3   FREE R VALUE                     : 0.2084

REMARK   3   FREE R VALUE TEST SET SIZE   (%) : 8.21  

REMARK   3   FREE R VALUE TEST SET COUNT      : 3882

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REMARK   3   NUMBER OF REFLECTIONS             : 107005   

REMARK   3   NUMBER OF REFLECTIONS (NON-ANOMALOUS) : 56251    

REMARK   3  

REMARK   3  FIT TO DATA USED IN REFINEMENT.

REMARK   3   R VALUE     (WORKING + TEST SET) : 0.1457

REMARK   3   R VALUE            (WORKING SET) : 0.15.34

REMARK   3   FREE R VALUE                     : 0.1997

REMARK   3   FREE R VALUE TEST SET SIZE   (%) : 3.51 

REMARK   3   FREE R VALUE TEST SET COUNT      : 3809

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NUMBER OF REFLECTIONS             : 48150     

REMARK   3   NUMBER OF REFLECTIONS (NON-ANOMALOUS) : 25296     

REMARK   3  

REMARK   3  FIT TO DATA USED IN REFINEMENT.

REMARK   3   R VALUE     (WORKING + TEST SET) : 0.1507

REMARK   3   R VALUE            (WORKING SET) : 0.1470

REMARK   3   FREE R VALUE                     : 0.1918

REMARK   3   FREE R VALUE TEST SET SIZE   (%) : 7.98  

REMARK   3   FREE R VALUE TEST SET COUNT      : 3841