Hybrid Pair Style with AIREBO and LJ/cut Potential

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1

Dear all,

I have three layers of atoms which are C, X, and C, respectively. I want to use airebo potential to describe the atomic intra-layer interaction and lj/cut for interlayer C/X and X/C interactions . Can it be achieved by the following code?

pair_style hybrid airebo 3.0 lj/cut 5.0
pair_coeff * * airebo CH.airebo C NULL C
pair_coeff 2 2 lj/cut 0.0000 3.382
pair_coeff 1 3 lj/cut 0.0000296 3.382

In other words, can this statement "pair_coeff 1 3 lj/cut 0.0000296 3.382" override the airebo setting by "pair_coeff * * airebo CH.airebo C NULL C " between atom type 1 and atom type 3? If not, any suggestion ?

Thanks for any help,
John

2

Dear all,

I have three layers of atoms which are C, X, and C, respectively. I
want to use airebo potential to describe the atomic intra-layer
interaction and lj/cut for interlayer C/X and X/C interactions . Can
it be achieved by the following code?

pair_style hybrid airebo 3.0 lj/cut 5.0
pair_coeff * * airebo CH.airebo C NULL C
pair_coeff 2 2 lj/cut 0.0000 3.382
pair_coeff 1 3 lj/cut 0.0000296 3.382

In other words, can this statement "pair_coeff 1 3 lj/cut 0.0000296
3.382" override the airebo setting by
"pair_coeff * * airebo CH.airebo C NULL C " between atom type 1 and
atom type 3?

no. AIREBO is not a pairwise additive force field, you cannot simply
override one group of pairs. that will result in bogus force
computations in the manybody contributions.
this is a recurring topic on this mailing list. in the future, please
first research the mailing list archives to find if your problem has
been answered before.

If not, any suggestion ?

you need to define multiple instances of AIREBO in your hybrid pair
style. please see the documentation for pair_style hybrid. it has an
example for "tersoff".

axel.