[gmx-users] question about Polak Ribiere conjugate gradient

[David]

On Mon, 2004-05-03 at 14:08, Hua Wong wrote:
> I am doing a minimization using the brand new GROMACS 3.2. It works fine on a system that previously lead to error with GROMACS 3.1.
> 
> I am working on a protein minimised under NAMD and wanted to minimise it further using GROMACS to correct some omega torsion problems. All seems to be fine, only I obtain a warning :
> 
> Stepsize too small, or no change in energy.
> Converged to machine precision,
> but not to the requested precision Fmax < 1e-06
> 
> I am using CG with GROMACS compiled in double precision. 
> 
try using
integrator = l-bfgs


> Here is the .mdp file I use.
> ##################################
> title                    = GMXminiomega
> cpp                      = /lib/cpp
> include                  = -I../top
> define                   = -DFLEXIBLE
> integrator               = cg
> emtol                    = 0.000001
> emstep                   = 0.01
> nstcgsteep               = 100
> nsteps                   = 3000
> nstxout                  = 50
> xtc_grps                 = Protein
> energygrps               = Protein
> nstlist                  = 5
> ns_type                  = grid
> rlist                    = 1.
> vdwtype                  = cut-off
> coulombtype              = cut-off
> rcoulomb                 = 1.
> rvdw                     = 1.
> 
> Is there anything I've forgotten ? 
> 
> Thanks
> _______________________________________________
> gmx-users mailing list
> gmx-users at gromacs.org
> http://www.gromacs.org/mailman/listinfo/gmx-users
> Please don't post (un)subscribe requests to the list. Use the 
> www interface or send it to gmx-users-request at gromacs.org.
-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://xray.bmc.uu.se/~spoel
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++