Thank you for suggestion Anagh. I took a look at this paper: “Reparameterization of the REBO-CHO potential for graphene oxide molecular dynamics simulations” Phys. Rev. B 84, 075460, 2011.
For molecule-water system, pcff FF reported to use successfully. So we decided use pcff for graphene-molecule-water, too.
Do you suggest use CHO-REBO for the total system or only for the graphene/graphene oxide part in the system?
I found it difficult to use pcff force filed together with other force fields (i.e. each material in the simulation system with a different FF), because pcff is a very complicated and using it in a hybrid pair_style was troublesome.
Thank you for suggestion Anagh. I took a look at this paper:
"Reparameterization of the REBO-CHO potential for graphene oxide molecular
dynamics simulations" Phys. Rev. B 84, 075460, 2011.
For molecule-water system, pcff FF reported to use successfully. So we
decided use pcff for graphene-molecule-water, too.
Do you suggest use CHO-REBO for the total system or only for the
graphene/graphene oxide part in the system?
that suggestion is nonsense and you should just ignore it.
I found it difficult to use pcff force filed together with other force
fields (i.e. each material in the simulation system with a different FF),
because pcff is a very complicated and using it in a hybrid pair_style was
troublesome.
yes, mixing force fields is a bad idea. in any case, the symptoms you
are seeing must be due to incorrectly using fix smd so that you will
have a bogus simulation with *any* force field.
axel.
Thank you for your response Dr. Axel.
Instead of this command:
fix PMF01 G smd cvel 20 0.0001 couple Mol auto auto auto 0
I used this and I didn’t get those warnings and errors:
fix PMF01 G smd cvel 20 0.0001 couple Mol auto auto 1 0
