monolayer sheet

[ramkrishna]

Dear Sir,
        Actually I want to see the band structure of ribbon as well as sheet, so what should I do for sheet? If I will increase the width only as wide as I want, then can I say, it is a sheet? I am not sure about that, please clarify this. And one more thing, if I want to build a MoS2 nanotube, then, how can I make that? Just by replacing the carbon atoms in the custom builder nanotube, then it does not give proper structure.

Regards
Ramkrishna

[Anders Blom]

No the sheet mean you have no vacuum, it will be periodic also in y (or x, I don't recall which direction you have). You can build a graphene sheet in VNL to compare.

I have no idea how to build a MoS2 nanotube - B-N yes, Zn-O yes, Si-C yes, but the stoichiometry AB2 I have never seen. If you have a reference for it one can look into it of course.

[Anders Blom]

Interesting, I found a reference for it, and the calculations were done with DFTB, which is now in ATK as well
http://prl.aps.org/abstract/PRL/v85/i1/p146_1

I guess how you construct it is to make a sheet and then roll it up, that shouldn't be too hard. In fact, in 12.2 there is a function "Expression Transformation" where you can apply a mathematical function to the coordinates. So you can map the sheet onto a circle.

I can perhaps play a bit with it during the weekend. But I don't promise anything, ok!

[ramkrishna]

Actually, I have seen this paper before and thats why I have asked you about that. I was trying to find that again and in the mean time, you have posted. Ok, I will try to make that using 12.2 builder, and please you also try this. 

[Anders Blom]

Hard to tell from the pictures...

For CBS calculation the system should have the same properties as an electrode, i.e. AB plane perpendicular to C.

The CBS is computed for a given k-point.

[ramkrishna]

Dear Sir,
        The pictures are generated by using the scripts which were posted by you and Mr Nordland in this topic (1st page) for orthorhombic monolayer supercell (to make a sheet) and a monolayer unit cell from bulk. A orthorhombic supersell can give a band structure for G, Z direction (or G,X or G, Y) where Z is (0,0,1/2) whether a monolayer unit cell from bulk can give a band structure for various symmetry points of the crystal. So, from the band structure, it is very hard for me to understand whether these two are physically equivalent or not. If you will clarify this then it will be very useful for my current research.

Regards
Ramkrishna   

[Anders Blom]

Built with VNL 12.2!

I need to work on it a little bit more, it has some glitches at this point although I think I can fix it rather simply.

Go 12.2!

[Anders Blom]

See http://quantumwise.com/forum/index.php?topic=1535.msg7655#msg7655

[ramkrishna]

Dear Sir,
         Thanks a lot for your kind help. 

Thanking you,
Ramkrishna