LAMMPS atomic coordinates to get relaxed band structure for bilayer graphene

LAMMPS
1

Hello,
Relaxation of the Twisted bilayer graphene systems are normally perform using LAMMPS.

I want to extract hopping parameters of tight binding model or continuum model to get the band structure calculations starting from the relaxed atomic coordinates.
I have relaxed atomic coordinates of bilayer graphene.

Can anyone assist me with this.

2

This is too generic a question. From your post it is not even clear what exactly you have done already and what you are trying to do now and at what step exactly you are struggling.

This sounds much more like a topic for a discussion with your adviser/tutor/supervisor.

3

Hello

I wrote a tutorial on the generation of graphene with VMD/topotool for LAMMPS, and one of the exercise is about creating a twisted bilayer :

Is this what you want to do?
Best,
Simon

4

Hopping rates can be computed from the electronic coupling between overlapping HOMO orbitals of two molecules, see for instance E.F. Valeev 2006 10.1021/ja061827h. For your graphene twisted bilayer, you have to figure out how to partition each layer into fragments, setting the correct QM/MM boundaries.
Interesting problem, but totally outside the scope of the LAMMPS forum :wink:

5

Hi Simon,

Thanks for the link. I have already generated graphene bilayer and relaxed using LAMMPS. My problem is to how to obtain hopping parameters from the atomic positions. I want to obtain continuum model band structure.

6

Hi,

I have relaxed coordinates of bilayer graphene which obtained from LAMMPS MD simulations.
I’m struggling with the part how exactly hopping parameters obtained from the atomic coordinates. In most of the studies people use DFT calculations to obtain the band structure. But I’m using LAMMPS relaxations and want to get hopping parameters for continuum model.

7

Hii,

Thanks for your suggestions. Nowadays people are using LAMMPS MD simulations to relax bilayer graphene and obtain continuum model band structure. I’m trying to do that

8

I already explained to you (LAMMPS density of states and Band structure calculation) that you cannot do such calculations with LAMMPS based on classical models.