[gmx-users] Constraint Error

[Jair]

I found an answer for this problem posted in 2003...

>> Have you run energy minimization? If not, do. If so, try it again, perhaps
>> with a lower tolerance and/or larger nsteps. Also, it could help to first
>> run md with position restraints, but *without* pressure coupling. If that
>> works, continue the run *with* pcoupl.

I also have a doubt about this issue. How can I rerun a position restrined 
with pcoupl after a previous run with no pcoupl.
Jair
IQ-UFRJ


On Wednesday 27 October 2004 08:21, Pawan Babel wrote:
> Hello gmx-users,
>
> My simulation was truncated due to following error.
>
> -----------------------
> Step 361846, time 723.692 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> max 1.104418 (between atoms 230 and 231) rms 0.098450
> bonds that rotated more than 30 degrees:
>  atom 1 atom 2  angle  previous, current, constraint length
>     218    219   90.0    0.6208   0.2209      0.1090
>     220    222   90.2    0.1084   0.1254      0.1090
>     230    231   90.0    0.2872   0.2125      0.1010
> Constraint error in algorithm Lincs at step 361846
>
> Step 361847, time 723.694 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> max 372413038592.000000 (between atoms 218 and 219) rms 24367785984.000000
> bonds that rotated more than 30 degrees:
>
> Constraint error in algorithm Lincs at step 361847
> Large VCM(group rest):      4.59862,     32.04837,      7.38148, ekin-cm:
> 9.02012e+07
>
> ------------------------
>
> Do anyone have idea how to solve this problem.
> thanks in advance
> Pawan
>