Dear LAMMPS users,
I am doing pullout test on a system consists of PE (united atom) and CNT. I am using Dreiding potential for PE and in one case I use AIREBO potential for CNT.
In most MD works on CNT pullout, AMBER potential have been used.
So can I use Dreiding potential instead of AMBER? If we can use both these potential to model this pullout test how this choice affects the results.
In literatures interaction between PE atoms is expressed as AMBER potential; but torsion term of AMBER is as follows:
Etor = SIGMA{V1cos(phi) +V2cos(2phi)+V3cos(3phi)+V6cos(6*phi)}
that this form of dihedral_style doesn’t exist in LAMMPS.
Anyone has suggestion for using this dihedral in LAMMPS?
Best regards,
Hamed
Dear LAMMPS users,
I am doing pullout test on a system consists of PE (united atom) and CNT. I
am using Dreiding potential for PE and in one case I use AIREBO potential
for CNT.
In most MD works on CNT pullout, AMBER potential have been used.
So can I use Dreiding potential instead of AMBER? If we can use both these
technically, you can use whatever you want.
how useful the result from the individual potential
will be, is on the other hand difficult to predict.
this is why people do validation simulations and
compare results against representative known
good experimental or simulation data.
potential to model this pullout test how this choice affects the results.
In literatures interaction between PE atoms is expressed as AMBER
potential; but torsion term of AMBER is as follows:
Etor = SIGMA{V1*cos(phi) +V2*cos(2*phi)+V3*cos(3*phi)+V6*cos(6*phi)}
that this form of dihedral_style doesn't exist in LAMMPS.
you can emulate this potential by using multiple harmonic
dihedrals. just define the same dihedral multiple times with
different types and the corresponding parameters.
cheers,
axel.
Sounds OK, though using Drieding and CHARMM in the same
simulation seems odd - not a normal thing to do with bio force fields.
I would specify only epsilon as 0.0, and sigma to some (arbitrary) non-zero
value.
Steve