Interlayer Layer distance is too large aprrox 100 Angstrom after Lammps relaxation .

[Ajit Singh Jhala]

Dear All, 

I am trying to relax the structure for bi layer graphene at all the possible angles using lammps(version - lammps-2Aug2023) , what we observe is all the structure after relaxation has constant interlayer distance of 100 Angstrom ,  also there is no corrugation between the layer. Could anyone please help. I am attaching all the input files.

Thanks

Ajit Singh Jhala

VNIT, Nagpur  

[Indrajit Maity]

Hi Ajit,

Typically, LAMMPS calculations are performed with periodic boundary conditions. Therefore, a distance of 103 Angstrom is equivalent to 103-Lz Angstroms. Here Lz is the box length along z-direction.

Any two atoms separated by x Angstroms are internally mapped considering the simulation box under periodic boundary conditions. It's important to be mindful of this.

A simple fix would be to shift all the atoms approximately halfway along the z-direction when providing their initial positions. This makes it easier to interpret the data during post-processing.

Best wishes, 

Indrajit

--
You received this message because you are subscribed to the Google Groups "Twister Help" group.
To unsubscribe from this group and stop receiving emails from it, send an email to twister-help...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/twister-help/b23850ac-07fa-4f4b-bfa7-92e1a4170f52n%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Ajit Singh Jhala]

Thank you for your help.

[Ajit Singh Jhala]

Dear Twister Help,

I hope this message finds you well. I am writing to request assistance with obtaining a sample SIESTA input file for the electronic band structure calculation of bilayer graphene.

I have been working on a project involving bilayer graphene, and despite my efforts, I have been unable to obtain the expected band structure for a twist angle of 21 degrees using my current input file. In an attempt to troubleshoot and refine my approach, I believe having access to a sample input file specifically tailored for this purpose would greatly benefit my efforts.

Attached, please find the input file I have been using thus far. Any insights or guidance you can provide on adjustments or improvements to this file would also be greatly appreciated.

Thank you in advance for your assistance.

Best regards, Ajit
VNIT NAGPUR 

[Ajit Singh Jhala]

Please Find attached file regarding the above mail here

[Indrajit Maity]

Hi Ajit,

You may want to check SIESTA manual and follow the discussions for the same. 

Based on a quick reading:

I recommend reducing the out-of-plane lattice constant to something like 20-25 Angstrom for SIESTA calculations. 

Also, as mentioned, you may want to shift the out-of-plane atoms halfway as the initial positions. You can easily achieve this by changing the z-axis of basis_pos_crys* files: from 0.0 to 0.5. And then rerun the same and take a look at the output structure for more intuitive visualization. 

Hope this helps.

Best wishes,

Indrajit

To view this discussion on the web visit https://groups.google.com/d/msgid/twister-help/f33a5b62-68e6-43af-a60b-6b2a2e94f4c8n%40googlegroups.com.