Hi,

To give you a rough idea on how to proceed:

1) build a clean surface (graphene in your case) and run a calculation with it;

2) add the Li atom(s) and repeat.

Notice that unless you what a full coverage of Li atom of the C surface, you need to have a supercell made of graphene unit cells to reduce the ratio Li/C.

If you are proficient with Python and Jupyter, I recommend ASE (atomistic simulation environment) as a tool to generate the both the pristine graphene, the supercell and then add the Li atoms. ASE will provide the atomic position and the lattice parameters that you will need to include into the Quantum ESPRESSO input. (Indeed, you can create the input directly within ASE.)

To complete your calculation you will need to:

1) Run a SCF calculation to determine the electronic ground state density. This step requires also the convergence of the simulation parameters (energy cut-offs, first Brillouin Zone sampling).

2) Run a non-SCF calculation for the band structure on a path

3) Run another non-SCF calculation for the DOS and PDOS on a mesh of the first Brillouin Zone.

You have to repeat the above steps for each of the configuration you want to investigate (i.e. changing the Li atom positions and their number).

I hope this helps,

Roberto

Roberto D'Agosta Thank you so much, that helps a lot!

Regarding absorption energy, is it calculated manually?

and is there any good source in this field?

Absorption energy is something that you need to calculate manually as the difference between the C+Li system - 1 Li - C system. Indeed you need to run the calculation for a single Li atom In vacuum.

What do you mean by “is there any good source in this field”? Do you mean references to study?

Regards,

Roberto

Roberto D'Agosta I'm really grateful for all this information, Thank you so much.

Yes, I mean references,

I am sorry no, I have not any references on top of my mind. But I am sure that in this case Google is your friend ;-)

Regards,

Roberto