[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[ccp4bb]: B-factor correction at low resolutin in cns



***  For details on how to be removed from this list visit the  ***
***          CCP4 home page http://www.ccp4.ac.uk         ***

Dear all,
When refining a structure at 3.5 angstrom with CNS, I get zero/negative B values after minimizing or annealing. I found it's the initial B-factor correction that lead to such change. I have to choose 'no correction'and give a overall B value of 20 to keep things normal, but I am not sure whether it is proper. However, the present model fits the electron density well (R/Rfree = 0.29/0.33).So can anyone tell me what's the main factor that causes the failure of B-factor correction? If it's a result of low resolution, what's the best overall B value should we choose? Thanks for your help.         

              leesea@moon.ibp.ac.cn
                 2002-09-28