Hi Everybody!

I am using phenix version 1.3b for refining a structure at 3 A resolution and total number of total reflections are 12680.

I have seen a provision in phenix to change the default maximal number of test flags to be generated and the fraction with this command line

 xray_data.r_free_flags.fraction=0.05 xray_data.r_free_flags.max_free=500



My queries are

1)when should somebody use this utility ??
2)what is minimum number of Rfree flags one should use on this resolution and this total number of reflections??


Any kind of suggestions will be appreciated.



Cheers!
Yusuf 





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