Hello all users,

I’m trying to solve for BN particle in water so this is the numbering of my

atoms:1-O

2-H

3-B

4-N

So I’m using this pair_coeff commands to use SPC/E for water, Tersoff for B

and N, and Lennard-Jones for cross relations. I carefully read the manual

about how to use pair_style hybrid command but the results are not as

expected, therefore I’m trying to understand the problem if it is in

potential definition or in post-processing. Do you think is there a problem

with these force field definitions? I understand that it should be

overwritten if we define the same type of atoms more than once in pair_coeff

so I guess once the tersoff is defined for B and N, water parameters and

cross relations should get the new values in the following pair_coeff

commands right? I will appreciate if you give me a couple of suggestions if

I am doing something wrong or how can I get better force field definition

for this problem? Thank you for your attention.pair_style hybrid lj/cut/coul/long tersoff coul/long 9.0

pair_coeff * * tersoff slotmant.tersoff NULL NULL B N

pair_coeff 1 1 lj/cut/coul/long 0.1533 3.166

pair_coeff 2 2 lj/cut/coul/long 0 0

pair_coeff 1 2 none

this one is *wrong*. you may not have lj interactions between H and O,

but you have to have coulomb.

you could have either:

pair_coeff 1 1 lj/cut/coul/long 0.1533 3.166

pair_coeff 1 2 coul/long

pair_coeff 2 2 coul/long

or:

pair_coeff 1 1 lj/cut/coul/long 0.1533 3.166

pair_coeff 1*2 2 lj/cut/coul/long 0 0

pair_coeff 1 3 lj/cut/coul/long 0.12 3.31

pair_coeff 1 4 lj/cut/coul/long 0.149 3.414

pair_coeff 2 3 none

pair_coeff 2 4 none

i don't understand this segment either. do you have coulomb

interaction between O and B or N? or only lj? and how about the

charges on H atoms?

axel.