[gmx-users] What can I to do with the problem: lincs warning and water can not be settled?

[Mark Abraham]

xiao shijun wrote:
> hi,
>   The simulation was OK. But when I changed the epsilon of some atoms to 
> get rid of LJ, lincs warning emerged as:
>         step 116 ; time 0.232  LINCS warning  ralative constraint 
> deviation after LINCS:
>                                                            rms 
> 0.168368,  max 4.765960 (between atoms 858 and 856)
>                                                            bonds that 
> rotated more than 30 degrees:
>  
>         t=0.232ps : water molecular starting at atom 17660 can not be 
> settled.
>         check for bad contact and/or reduce the timestep.
>        then the warning happened every step untill the programm crashed.
>   Thanks for your discussion!!

See 
http://oldwiki.gromacs.org/index.php/Errors#LINCS.2FSETTLE.2FSHAKE_warnings

You unbalanced your forcefield, so it's no surprise that it doesn't work 
correctly any more.

Mark