about airebo potential

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1

Dear All,

A long time ago I did a MD simulation of polyethylene using airebo potential, and I encountered some problems. Then you reminded me to remove all definitions of bonds, angles, and dihedrals from the data file, as shown in below message. The simulation was indeed ok after I removed relative definitions. However, I can not understand why should I remove the definitions. Is it substantial requirement by the airebo potential? Most importantly, how will the bond, angle, and dihedral behaviors be described if removing their definitions from data file? I guess you should have answers to my above questions! Your comments will be highly appreciated!

Best regards,
Yusong He

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This answer applies to all of the many-body potentials
in LAMMPS, e.g. ReaxFF, AIREBO, Tersoff, EAM.

It makes little sense to explicitly hardwire bonds, angles,
etc between atoms modeled with these potentials
with a bond or angle style. The
potentials are designed to model the interactions between
atoms without such terms and to allow "bonds" to freely
form and break as the atoms move. Adding explicit
bonds is unphysical and will inhibit this process.

Steve