[gmx-users] about temperature coupling

Justin A. Lemkul jalemkul at vt.edu
Mon Nov 21 04:34:17 CET 2011

RuiTing Zhang wrote:
> Dear gmxusers.
> I have problems about temperature coupling. Here is my parameter for temperature coupling.
> ; Berendsen temperature coupling is on in two groups
> Tcoupl              =  berendsen
> tc-grps		    =  System
> tau_t               =  0.1
> ref_t               =  298
> I used "g_traj -f traj.xtc -s topol.tpr -ot temp.xvg" to check the temperature for all time frames. The temperature of the system seems to fluctuate around 200K. My system consists 1000 waters and 18 NA and 18 CL. And the SOL alone has such problem. Could anyone give me a clue of what may be the cause of the misfit of the temperature? Thank you very much!  

Note that g_traj warns that constraints are not taken into consideration when 
printing temperatures.  This is likely where the discrepancy lies.


> Best Regards
> rtzhang


Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080


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