[gmx-users] Re: [ atomtypes ] are not case sensitive?

Justin Lemkul jalemkul at vt.edu
Sun Aug 5 18:24:24 CEST 2012

On 8/5/12 12:16 PM, juanjuan0618 wrote:
> I'm sorry to disturb you again.
> The previous questions have been solved. I delete the [ atomtypes ]
> description in the CO2.itp file and then the error is removed.
> But I have another question to ask you, can you tell me the meaning of
> molname, nrexcl, resnr and residue in the itp files, I read the manual, but

molname = molecule type name
nrexcl = number of bonds that determine exclusions
resnr = residue number

> I could not understand the directions. What is the number of CO2's nrexcl?
> And the other question is when  running "mdrun", it prompts me
>       Fatal error:
>       More than one settle type.
>       Suggestion: change the least use settle constraints into 3 normal
> constraints.
>    What should I do to solve this question?

You're using the SETTLE algorithm for both CO2 and water.  You can't do that. 
You should probably construct the CO2 molecule in a more robust way, i.e.:




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


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