Hi U Well if you can tell me the total number of atoms in your PDB file (NOT counting any H atoms), I can estimate a range for the expected optimal Rfree assuming your value of Rwork and the no of reflns in your working set (~= 19x1715 = 32585 right?). If you have any NCS I can't promise my estimate will be very accurate, because it will also depend a lot on the nature of the NCS, how you selected your test set, how you restrained the NCS etc. I can already tell you that the range of optimal Rfree (+/- 3 sd's) will be ~ +/- 0.014 (i.e. +/- 3x0.267/sqrt(2x1715)) from whatever is the expected value.
Cheers -- Ian > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of U Sam > Sent: 20 June 2008 21:23 > To: Mark J. van Raaij; [email protected] > Subject: RE: [ccp4bb] How many reflections for Rfree? > > I use CCP4i, refmac5 for the refinement using data of 2.45 > angstrom. My R and Rfree is 0.182 and 0.267 respectively. For > calculating Rfree ,5% of random data (1715 reflections) was > used . So I see there is a difference of about 8.5% between R > and Rfree. Is this difference reasonable ? > Any idea how can I improve Rfree and difference between R and > Rfree gets less than 5%. > Thanks, > > _________________________________________________________________ > Need to know now? Get instant answers with Windows Live Messenger. > http://www.windowslive.com/messenger/connect_your_way.html?oci > d=TXT_TAGLM_WL_Refresh_messenger_062008 > > Disclaimer This communication is confidential and may contain privileged information intended solely for the named addressee(s). It may not be used or disclosed except for the purpose for which it has been sent. If you are not the intended recipient you must not review, use, disclose, copy, distribute or take any action in reliance upon it. If you have received this communication in error, please notify Astex Therapeutics Ltd by emailing [EMAIL PROTECTED] and destroy all copies of the message and any attached documents. Astex Therapeutics Ltd monitors, controls and protects all its messaging traffic in compliance with its corporate email policy. The Company accepts no liability or responsibility for any onward transmission or use of emails and attachments having left the Astex Therapeutics domain. Unless expressly stated, opinions in this message are those of the individual sender and not of Astex Therapeutics Ltd. The recipient should check this email and any attachments for the presence of computer viruses. Astex Therapeutics Ltd accepts no liability for damage caused by any virus transmitted by this email. E-mail is susceptible to data corruption, interception, unauthorized amendment, and tampering, Astex Therapeutics Ltd only send and receive e-mails on the basis that the Company is not liable for any such alteration or any consequences thereof. Astex Therapeutics Ltd., Registered in England at 436 Cambridge Science Park, Cambridge CB4 0QA under number 3751674
