Hybrid Carbon and Hydrogen

Dear All,

I want to use different interatomic potentials as follows:

In Graphene Plane between C-C: Tersoff
Between C of Graphene sheet and C of Methyl: Airebo
Between C and H of Methyl: Airebo

Would you mind letting me know how can I use the Hybrid Potential for this simulation?

Regards,

Dear All,

I want to use different interatomic potentials as follows:

In Graphene Plane between C-C: Tersoff
Between C of Graphene sheet and C of Methyl: Airebo
Between C and H of Methyl: Airebo

Would you mind letting me know how can I use the Hybrid Potential for this
simulation?

​please have a look at the documentation.​

​http://lammps.sandia.gov/doc/pair_hybrid.html

​...and please also note that both potentials you mention are manybody
potentials and thus not pairwise additive. consequently those cannot be
combined without introduction ​of significant inconsistencies unless each
is applied to a separate group of atoms and the inter-group interactions
are computed with a pairwise additive potential.

what is the justification for such a complex setup anyway? why don't you
just use airebo for all and be done with it?

Methyl has been functionalized in the graphene sheet in my study. I don’t know what is the problem when I use CH.airebo potential in my model? the bonding between C-C is never broken. I was wondering it was because of Methyl but when I simulated pure graphene with CH.airebo potential, after tensile loading, there is no damage in the bonding when the strain rate is applied. What is the problem with this potential or my setup?

Methyl has been functionalized in the graphene sheet in my study. I don't
know what is the problem when I use CH.airebo potential in my model? the
bonding between C-C is never broken. I was wondering it was because of
Methyl but when I simulated pure graphene with CH.airebo potential, after
tensile loading, there is no damage in the bonding when the strain rate is
applied. What is the problem with this potential or my setup?

​how on earth should *I* know this??​ i don't own a crystal ball or have
ESP.

​how should using an inconsistent potential setup improve things?

it would be much better to discuss your problems with your adviser and your
colleagues.​

Methyl has been functionalized in the graphene sheet in my study. I don't
know what is the problem when I use CH.airebo potential in my model? the
bonding between C-C is never broken. I was wondering it was because of
Methyl but when I simulated pure graphene with

​there is one more issue: how do you determine whether bonds are broken?
how do you know, that you don't have a problem with this and not the
simulation itself?​