how to assign force field parametres

hi,
i am making data file for poly aniline.whike doing that i am facing problem to chose forcefield parametres
lie bond coefficients angle coefficient and torsional coffecints,where can i get full information regarding this
please help me thanks in advance

thanks
naresh

hi,
i am making data file for poly aniline.whike doing that i am facing problem
to chose forcefield parametres
lie bond coefficients angle coefficient and torsional coffecints,where can i
get full information regarding this
please help me thanks in advance

you have to look up force field parameters in the literature
or assign them from one of the generic force fields.

lammps does have any internal functionality for that,
you would have to do that manually, or write custom scripts
( examples at http://sites.google.com/site/akohlmey/software/topotools/topotools-tutorial---part-2
)
or use some other package and then convert the force field
data so that lammps can read it.

cheers,
    axel.
there are some converters for ex