This is interesting. Would it be possible to have refmac provide some info WHICH U (i.e. atom) got negative EV ? I did not find anything and I use monitor many per default.
Thx, BR -----Original Message----- From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of Aaron Oakley Sent: Thursday, September 03, 2009 7:38 PM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Problem in MAKE_U_POSITIVE If one of its eigenvalues of the ANISOU matrix is negative, the matrix is non-positive definite leading to the MAKE_U_POSITIVE problem. I understand that this could indicate that an atom is sitting on a saddle point between two minima and that the atom could be split into two conformers. I had this happen once. Cheers, a++ > On Wed, 2009-09-02 at 19:26 -0700, Bernhard Rupp wrote: > > Hi there - > > > > > > > > a transient message appears during anisotropic refinement > > > > CCP4 6.1: Refmac_5.5.0071 > > > > Problem in MAKE_U_POSITIVE > > > > that seems to have no further consequences. I guess that means that > > some > > > > elements in a U tensor lead to a divergent behavior, but > details evade > > me. > > > > > > > > Just curious.... > > > > BR > > > > > > > > ----------------------------------------------------------------- > > > > Bernhard Rupp > > > > b...@ruppweb.org > > > > http://www.ruppweb.org/ > > > > ----------------------------------------------------------------- > > > > Anything is possible if you don't know > > > > what you are talking about. > > > > ----------------------------------------------------------------- > > > > > > > > > > > > > -- > ************************************************************** > ********* > * > * > * Dr. Martyn Winn > * > * > * > * STFC Daresbury Laboratory, Daresbury, Warrington, WA4 > 4AD, U.K. * > * Tel: +44 1925 603455 E-mail: martyn.w...@stfc.ac.uk > * > * Fax: +44 1925 603825 Skype name: martyn.winn > * > * URL: http://www.ccp4.ac.uk/martyn/ > * > ************************************************************** > ********* > =
