Dear Lammps users, I am trying to use the force/tally compute to get per atom forces on a group exerted by a different group of atoms. My pair style consists of two body as well as many body potentials (LJ , SW and TERSOFF).

However, the groups among which I want the force/tally to be computed interact only through two body interactions. For example, pair 1-1 and 2-2 have many body terms but pair 1-2 have exclusive 2 body interactions. And, it is these 1-2 forces I am interested in.

When I try to compute force/tally with the setup above, I run into an error “Compute force/tally used with incompatible pair style”, which arises from the fact that I have many body interactions (many body flag is ON and simply ignoring this condition doesn’t seem to work).

Is there a work around for this problem?

Thanks a lot in advance.

Cheers,

Vikram Reddy Ardham

Theoretical Physical Chemistry group,

TU Darmstadt, Germany.

Dear Lammps users, I am trying to use the force/tally compute to get per

atom forces on a group exerted by a different group of atoms. My pair style

consists of two body as well as many body potentials (LJ , SW and TERSOFF).

However, the groups among which I want the force/tally to be computed

interact only through two body interactions. For example, pair 1-1 and 2-2

have many body terms but pair 1-2 have exclusive 2 body interactions. And,

it is these 1-2 forces I am interested in.

When I try to compute force/tally with the setup above, I run into an

error “Compute force/tally used with incompatible pair style”, which arises

from the fact that I have many body interactions (many body flag is ON and

simply ignoring this condition doesn’t seem to work).

no, it cannot work, since there is not yet support for hybrid pair styles.

i've programmed the changes only yesterday:

https://sourceforge.net/p/lammps/mailman/message/35798202/

to have this apply selectively to hybrid substyles will require additional

programming. i already have an idea how to do it and will work in it later

today.

axel.