Hi
I was trying to do tensile simulation upon graphene.
My code is like below:
Input file for uniaxial tensile loading of nanoplaete
nano project, 2020
------------------------ INITIALIZATION ----------------------------
units metal
dimension 3
boundary p p p
atom_style atomic
----------------------- ATOM DEFINITION ----------------------------
lattice fcc 2.46
region whole block 0 15 0 1 0 15
create_box 1 whole
lattice fcc 2.46 orient x 1 0 0 orient y 0 1 0 orient z 0 0 1
create_atoms 1 region whole
mass * 12.0107
velocity all create 300 123456 mom yes rot yes
----------------------- FORCE FIELDS ------------------------------
pair_style airebo 2.0 1 0
pair_coeff * * CH.airebo C
------------------------- SETTINGS ---------------------------------
there are plenty of tools available that can build graphene sheet geometries and there are also tools available that can convert geometries into data files for LAMMPS. also, there are instructions available how to construct such geometries, which allow you to write your own custom script or program and have it output a LAMMPS data file directly. it is also possible to use LAMMPS directly, by defining a suitable custom lattice.
just do a little (creative) web search and you should find the tools or at least suggestions for (combinations of) tools or examples of inputs.
axel.
Try this in place of your lattice command:
lattice custom 2.46 &
a1 1 0 0 &
a2 0 1.732050807569 0 &
a3 0 0 3.35 &
basis 0 0 0 &
basis 0.5 0.166666666667 0 &
basis 0.5 0.5 0 &
basis 0.0 0.666666666667 0 &
This will give you the hexagonal graphene lattice. If you still have issues with the box exploding even with this lattice, instead of starting the system at 300 K, I recommend starting from around 5 K or so and ramping up to 300 K over 50 - 100 ps. That’s what I do when transferring a system from a fixed-bond force field to ReaxFF.
I’ve also attached the script that this lattice command is from. You can find it on Dr. Penev’s website: http://penev.objectis.net/resources.
Will
in.graphene.lmp (730 Bytes)