[lammps-users] coarse-grained molecular dynamics


I am new to LAMMPS. Recently I have tried to run a coarse-grained
molecular dynamics simulation. I could let it run but has never been
able to finish even one timestep. The system in the attached files has
been reduced to a every small one for debugging and test. Could some
one help me take a look at the attached files and suggest? I really
appreciate that.

Best regards,
Dongsheng Wu

data.nowater (39.7 KB)

in.nowater (293 Bytes)

I presume you got this error:

ERROR: Must define pair_style before Pair Coeffs

If you put the pair_style line before the read_data (since
your data file has pair coeffs in it), then it runs
fine. Also use thermo 1 if you want to see output
before the end of the run = step 10000.


Hi Steve,

I did not get any error. That is why I have wasted the whole week for
debugging the problem. But your suggestion did solve the problem.
Thank you so much.

Best regards,

P.S. Maybe the code need to be revised to provide more friendly
feedback? But I think I would better use this mailing list more often
in the future.

I don't see how you didn't get that error with the
input script you posted. It occurs immediately
when the data file is read at the beginning of the script.
And the error message tells you what the problem
is. If you're running on some parallel machine, configured
so that you don't see error messages output from
the ocde, then you should look into the machine config.
I've never seen any machine that doesn't display an error
message that LAMMPS generates.