Calculating Surface Band Structure

Message

mrm · #1 Post by **mrm** » Sat Feb 28, 2009 2:48 am

Dear All,

I am interested in calculating the surface band structure of an adsorbed monolayer (square lattice) on top of an fcc metal slab (about 7 layers). I believe I have been successful in calculating the site-projected DOS of the surface monolayer. I am also familiar with how to calculate the bandstructure of a bulk material. My questions are:

1) How does the surface bandstructure calculation differ from a bulk calculation?
2) How do I tell VASP to focus only on the surface layer to get bandstructure?
3) Is it possible to tell VASP to focus on a specific region on the surface monolayer for the bandstructure?
4) what should my k-points high symmetry directions be if the surface layer is a square lattice but the substrate slab is an fcc crystal?
5) Any other advice or hints you can give would be greatly appreciated.

Thanks very much for your help.

<span class='smallblacktext'>[ Edited ]</span>

#2 Post by **admin** » Mon Mar 02, 2009 10:50 am

1+4) please have a look at standard surface physics textbooks.
2+3) this should be done on the plotting level: the calculation itself will include all bands, but eg p4vasp gives you the opportunity to pick out the 'surface bands' from the bulk(like) continuum, by selecting the atoms and the partial charge contibution of these atoms to the state.

mrm · #3 Post by **mrm** » Thu Mar 05, 2009 10:49 pm

Dear Admin,

Thank you very much for your quick reply to my question. I believe I understand. I hope to try p4vasp.

I have two more brief questions I hope you can help with:

1) what does p4vasp look for when determining if some of the bands are "surface-like" vs "bulk-like"? Is it looking for exponentially decaying wavefunctions into the bulk?

2) Is it looking at the WAVECAR file or a combination of files?

I might be interested in writing my own code to filter out the surface bands but need to know where the relevant info is kept and what determines a surface-band. Thank you in advance for your help.

#4 Post by **admin** » Tue Mar 10, 2009 2:04 pm

For questions related to p4vasp, please in general have a look in the p4vasp-forum
1) no, you have to define the atom(s) in the surface layer and choose a percentage of partial charge which has to be located in that particular atom(s) at least.
2) no the wavefunctions and their decay are not used.

mrm · #5 Post by **mrm** » Thu Mar 26, 2009 11:58 pm

Dear Head Admin,

Thank you for your help. Sorry I took so long to reply. I appreciate your time and advice.