Bond order potential (bop) on carbon clusters seem to generate unphysical results

Dear all,

I’m newbie in LAMMPS, I tried to calculate the energy minimization for carbon clusters with an analytical bond order potential. The parameter file I used was “CCu_V2.bop.table”. I tried to use a linear chain structure as input. However, after structure minimization, the carbons atoms become dissociated and results seem quite unphysical. Any suggestions will be much appreciated. I attach my input file and structural results for your convenience. Thanks.

Best Wafa

in.C19 (328 Bytes)

structuralresults.xyz (292 Bytes)

Dear all,

I'm newbie in LAMMPS, I tried to calculate the energy minimization for
carbon clusters with an analytical bond order potential. The parameter file
I used was "CCu_V2.bop.table". I tried to use a linear chain structure as
input. However, after structure minimization, the carbons atoms become
dissociated and results seem quite unphysical. Any suggestions will be much
appreciated. I attach my input file and structural results for your
convenience. Thanks.

as a beginner, you should be rather hesitant from making such bold
claims as in your subject line.

some items for you to think about:

- what *is* the expected behavior?
- do other potentials on the same system give the same or a different behavior?
- keep in mind that minimization algorithms only find local minima and
that position updates may be limited by the algorithm and symmetry of
the system.
- have you tried other ways to minimize the structure?

axel.

You can also ask the authors of the BOP potential
in LAMMPS (see the top of the pair_bop.cpp file)
if the potential can model the scenario you are
proposing. I.e. ask the experts.

Steve