Hi,

I am trying to restrain an ion that is coordinated by a few protein atoms, to avoid that the ion might fly off. The simulation should be run on a GPU (with OpenMM) and implicit solvent. First I tried to restrain the ion using bonds of type 6, but harmonic potentials are not supported by OpenMM. Turning the restraint into a normal bond (type 1) would be fine since I only constrain bond lengths of hydrogens. However, that gives a grompp error,

"Cannot find length for atoms 386-2262 involved in angle"

meaning that the function find_gb_bondlength in topio.c does not find a bond length for the ion-protein atom bond, although the bond length is clearly defined in the topology.

I am a bit stuck now. Does anyone know how one could introduce some kind of distance restraint with OpenMM and implicit solvent?

I am using gmx 4.5.3 and OpenMM 2.0.

Thanks a lot,

Jochen

--
---------------------------------------------------
Dr. Jochen Hub
Computational and Systems Biology
Dept. of Cell&  Molecular Biology
Uppsala University. Box 596, 75124 Uppsala, Sweden.
Phone: +46-18-4715056 Fax: +46-18-511755
http://xray.bmc.uu.se/~jochen/index.html
---------------------------------------------------

--
gmx-users mailing list    gmx-users@gromacs.org
http://lists.gromacs.org/mailman/listinfo/gmx-users
Please search the archive at 
http://www.gromacs.org/Support/Mailing_Lists/Search before posting!
Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org.
Can't post? Read http://www.gromacs.org/Support/Mailing_Lists

Reply via email to