[gmx-users] lincs warning

[Rongliang Wu]

Hello, gmx-users，
	   i am just simulating a single PEO chain in a large box(vacuum), the EM step went perfectly well for steep and cg, but after MD has started there came the following warnings: 

Step 1432, time 2.864 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 1.600984 (between atoms 141 and 142) rms 0.134828
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
    141    142   90.0    0.1000   0.2458      0.0945
Wrote pdb files with previous and current coordinates

Step 1433, time 2.866 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 0.027914 (between atoms 141 and 142) rms 0.002435
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
    141    142   90.0    0.2458   0.0971      0.0945

Step 1434, time 2.868 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 1.672527 (between atoms 141 and 142) rms 0.140852
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
    141    142   90.0    0.0971   0.2526      0.0945

………………

and in a few seconds the core dumped, and system collapsed.

i was using oplsaa force field and the [ pairs ] are removed as refered by the mannual
i wonder where the problem might exists. any suggestion will be greatly appreciated!


Regards

Thanks
 				

　　　　　　　　Rongliang Wu
　　　　　　　　wurl04 at iccas.ac.cn
　　　　　　　　　　2006-04-04