[gmx-users] what does the error mean

[xiaoyi li]

Hello,

My system is composed from two proteins, two axt molecules and a box of
water. During the MD run by Gromacs, it is always stopped at 200ps or
less because of error.

At the end of .log file, it shows:

Constraint error in algorithm Lincs at step 10767
 
t = 21.534 ps: Water molecule starting at atom 45552 can not be settled.
Check for bad contacts and/or reduce the timestep.Wrote pdb files with previous
and current coordinates
Grid: -2147483648 x -2147483648 x -2147483648 cells
Fatal error: ci = -1 should be in 0 .. -1 [FILE nsgrid.c, LINE 211]

What should I do?

Thanks a lot!

xiaoyi