question about pair style

Dear lammps users,

I have a question about using pair_style command.

I have clay particles with clayff force field and water with charmm force field. In this case, there is a problem to write the pair_coeff of water atoms interact with clay atoms. I do not know what kind of force field I can choose. Is there any way to solve the problem?
Thank you!

Miao-Chun

Dear lammps users,

I have a question about using pair_style command.

I have clay particles with clayff force field and water with charmm force
field. In this case, there is a problem to write the pair_coeff of water
atoms interact with clay atoms. I do not know what kind of force field I
can choose. Is there any way to solve the problem?

​you need to find a water potential that is compatible with clayff or even
specifically parameterized for it.
there should be publications on this. you may need to try out a few
variants, as people tend to make all kinds of more-or-less dubious hacks
with varying success for these things.

in general, it is considered problematic to mix and match parameter sets
from different force fields, especially if they are coupled via coulomb.
different (conventional) force fields with partial charges have a different
balance between LJ and Coulomb for their non-bonded interactions and often
requirements for solvent and strategies to keep things consistent.

should there be no viable published information (i cannot imagine this,
considering the subject), then you may have to teach yourself how to derive
and test parameters (an often non-trivial work, especially for solvents and
particularly for water).

overall, this is not at all a problem with pair_style, but a problem of
planning your project and your research and validating your models. in
those cases, a thorough survey of the literature is usually the best option.

axel.