Hi John, Here is the output I get :
Powell::step: irregular exit: Line search abandoned: gradient may be incorrect *-- POWELL ------ step= 20 --- stepsize= 0.01000 --- energy evals= 60 -* | E(poten)= -1547.2976913 grad= 6.3938934 ANGL= 342.4001843 | | BOND= 15.9849558 CDIH= 12.8295295 IMPR= 5.8861335 | | ORIE= -583.0114776 PLAN= 56.2931712 RAMA= -1690.4008379 | | VDW= 11.8511017 noe= 280.8695484 I want it to do 2000 steps of cartesian minimization, but it quits after only 20-50. I have been using the same force constants as in the rna_refi example. Maybe my rama/orie terms have too much force? Thanks, Gokul Quoting John Kuszewski <johnk at mail.nih.gov>: > Hi Gokul, > > Could you send me the relevant output? > > Most likely, it just means that the minimizer got stuck. The > gradients from the orie and rama terms are approximate, because > they're coming from databases of known structures, and so they can > occasionally be too rough for the minimizer. > > If all the experimental terms (NOE, RDC, etc) have acceptable > agreements, then you can probably take the final coordinates from > your rama + orie structures as converged. > > --JK > > On Mar 3, 2008, at 12:33 PM, Gokul Ramaswami wrote: > >> Hello Xplor users, >> >> I am trying to refine an rna molecule using the rama and orie database >> potentials. The problem is during the final minimization I get an >> error message stating that the gradient may be incorrect and the >> program terminates. If I take out these 2 potentials, then the >> minimization occurs without error, but the structure has poor base >> stacking. Any help would be greatly appreciated. >> >> Thanks, >> >> Gokul >> _______________________________________________ >> Xplor-nih mailing list >> Xplor-nih at nmr.cit.nih.gov >> http://dcb.cit.nih.gov/mailman/listinfo/xplor-nih > > > >
