Reg: Bond information using tersoff potential

Dear all

I am running simulations for graphene using tersoff potential. I am not using any bond style. At the time of simulation there is bond breakage and formation in my system. I am visualizing the new bonds but how to output the bond information.

When i am writing the data file at the end, the bond information it is giving is same as that in initial data file. When i used compute property/local it is also giving the same initial data.

I am wondering if there is some special command for printing this information or i am doing something wrong.

Please if anyone give some suggestions, it will be helpful.

Dear all

I am running simulations for graphene using tersoff potential. I am not
using any bond style. At the time of simulation there is bond breakage and
formation in my system. I am visualizing the new bonds but how to output the
bond information.
When i am writing the data file at the end, the bond information it is
giving is same as that in initial data file. When i used compute
property/local it is also giving the same initial data.
I am wondering if there is some special command for printing this
information or i am doing something wrong.

the problem is that you don't understand how the tersoff potential
works. there are no explicit bonds in tersoff, the bonding topology
and resulting contributions to the overall interaction energy and
resulting forces are computed on the fly. this is what takes tersoff
from a simple, non-directional, and pairwise-additive potential to a
manybody potential. thus this information about the bond topology is
not available through any of the facilities in LAMMPS that are made
for explicit bonds. in fact, if you are starting a simulation that
does use tersoff *and* explicit bonds for those atoms, you are making
a mistake and your simulation will be bogus.

visualization programs usually have no specific knowledge of the
chemistry of a system, but may use simple geometric criteria for
assigning bonds.

axel.