[lammps-users] pair distance < table inner cutoff error problem

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1


Dear Dr. Alex,
Thank you for your valuable comments. Till now, I could not solve this problem. I enclose the input file and potential data file and read_data file.

Data6.txt is read_data file
dataa.table, data.table and dataaa.table potential files
input.txt is input file.

I request you to check my input file and potential data file so that I can remove this problem. Give adequate suggestion.

Thanks and best regards
Dr. Sankar, MAE, NTU, Singapore


— On Thu, 27/1/11, Axel Kohlmeyer <akohlmey@…29…> wrote:



> From: Axel Kohlmeyer [email protected]
> Subject: Re: [lammps-users] pair distance < table inner cutoff error problem
> To: “sankar kumar” <sankar_20005@…16…>
> Cc: [email protected]
> Date: Thursday, 27 January, 2011, 7:09 AM
>
> On Thu, Jan 27, 2011 at 2:58 AM, sankar kumar <sankar_20005@…16…> wrote:
> >
> > I am working on course grain bead spring model (fene)using lammps md simulator. I am using some potentials as tables using pair_style table command which are not in lammps… But after running it shows pair_distance < table inner cutoff error. Please inform me how I can solve this problem.
>
> some particles are obviously getting too close. you have to generate your
> tables in such a way so that they include smaller r values.
>
> please note that when using tabulated potentials, the “edges” are always
> a bit unphysical so it is good practice to make the tables to significantly
> beyond those ranges and use a high enough resolution.
>
> cheers,
> axel.
>
> > Sincerely yours
> > Dr. Sankar
> > NTU, Singapore
> >
> > ------------------------------------------------------------------------------
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>
> –
> Dr. Axel Kohlmeyer
> [email protected] http://goo.gl/1wk0
>
> Institute for Computational Molecular Science
> Temple University, Philadelphia PA, USA.

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input.txt (2.21 KB)

data6.txt (7.2 KB)

data.table (105 KB)

dataa.table (52.8 KB)

dataaa.table (52.8 KB)

2

Dear Dr. Alex,
Thank you for your valuable comments. Till now, I could not solve this problem. I enclose the input file and potential data file and read_data file.

Data6.txt is read_data file
dataa.table, data.table and dataaa.table potential files
input.txt is input file.

I request you to check my input file and potential data file so that I can remove this problem. Give adequate suggestion.

if just you want me to do your work. then you
will have to compensate me for my time.

i already gave you my opinion. you either have
some bad configuration that pushes atoms closer
together than they should be, or your potential tables
don't cover a large enough distance range.

both are issues that you can easily analyse
and correct yourself.

if you have proof that there is a problem in LAMMPS
and not your input, i am happy to help.

axel.

3

I'll say it another way. The error you are getting
is b/c a pair of particles became closer to each
other than the minimum distance you defined in
your tabulated potentail. There is nothing
LAMMPS can do at that point but print an error
and stop. So you have to fix your model (either
the dynamics is bad or you need to extend the
range of the tabulation) and
no one can do that except you.

Steve