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:[log in to unmask]] On Behalf Of Aaron
Oakley
Sent: Thursday, September 03, 2009 7:38 PM
To: [log in to unmask]
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
> >
> > [log in to unmask]
> >
> > 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: [log in to unmask]
> *
> * Fax: +44 1925 603825 Skype name: martyn.winn
> *
> * URL: http://www.ccp4.ac.uk/martyn/
> *
> **************************************************************
> *********
> =
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