IUBio GIL .. BIOSCI/Bionet News .. Biosequences .. Software .. FTP

Powell minimization

Michael Nilges nilges at NMR.EMBL-Heidelberg.DE
Wed Dec 4 09:57:08 EST 1996

> Dear X-Plor users,
> when I'm trying to minimize protein structures (models and NMR structures
> using constraints) some minimizations abort with the message 'line search
> abandoned'. Has anybody ever come across this? Any idea what's going wrong?
> the problem occurs with X-Plor 3.1 and 3.843.

This is often related to a discontinuity or kink in the energy function  
(which appears for example if you truncate the electrostatics or vdW  
potential, or use a tolerance <> 0 for fcalc or relaxation matrix  
calculations). Sometimes it helps to restart the powell minimization (i.e.  
instead of doing 200 steps, do 5 times 40)


More information about the X-plor mailing list

Send comments to us at archive@iubioarchive.bio.net