Hi lammps-users

I set the electrostatic potential, pairwise potential for non-bonded atoms and harmonic potential for bond and angles. Then I used compute property/atom command to calculate the force of each atom I am interested in. I have read this post http://lammps.sandia.gov/threads/msg15551.html which says that the electrostatic potential can not be decomposed to atoms. So, the output of the property/atom command in my case will just include the pairwise potential for non-bonded atoms and harmonic potential for bond and angles (Let assume all the interested atoms have bond and angles). Is my understanding right? If it is wrong, what are components I get from this command?

Fan Li

Hi lammps-users

I set the electrostatic potential, pairwise potential for non-bonded atoms

and harmonic potential for bond and angles. Then I used compute

property/atom command to calculate the force of each atom I am interested

in.

compute property/atom does not do any kind of computation, it merely gives

access to properties that are assigned to atoms or computed elsewhere by

storing a copy of them.

I have read this post LAMMPS Molecular Dynamics Simulator which

says that the electrostatic potential can not be decomposed to atoms.

that is not correct. you *can* get per-atom energy contributions from

k-space (and you *do* get the per-atom force contributions included in

fx/fy/fz). what you can *not* get from kspace is to decompose those

interactions into pair-wise contributions. but compute property/atom does

not do that, anyway.

So, the output of the property/atom command in my case will just include

the pairwise potential for non-bonded atoms and harmonic potential for bond

and angles (Let assume all the interested atoms have bond and angles). Is

my understanding right? If it is wrong, what are components I get from

this command?

what you get is what you request. please read the documentation of the

command much more carefully. it lists what it does.

axel.