[gmx-users] Write force on a single particle

Justin Lemkul jalemkul at vt.edu
Wed May 31 02:11:53 CEST 2017

On 5/30/17 5:48 AM, simon.grosse-holz at fau.de wrote:
> Dear All,
> is it possible to write the forces of only one (type of) particle to the 
> trajectory?
> I am using GROMACS to simulate the dispersion of a hydrophobic particle in a big 
> box of water and am interested in the force acting on the particle. Simply 
> writing all the forces to the trajectory (via nstfout) also writes all the 
> forces on the water molecules, which is a lot of data that actually I do not 
> need. For the compressed trajectory output I can specify the groups to write, 
> which would perfectly solve my problem, if the compressed trajectories could 
> hold forces. That, however, is not the case (as far as I know; is that 
> correct?). So is there any other way to get only the force acting on the one 
> particle?

The only solution of which I am aware is to do a short interval of simulation 
writing a full .trr, post-process to save only what you want, then continue with 
another interval, etc.



Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441


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