[DFTB-Plus-User] Band structure for H chain

[R.Perez Garcia]

Dear DFTB specialists,

I been struggling with the plot of the 
band structure for my system. Unfortunately they look very 
unattractive...(if it is possible to say so:).

SO I decide to 
make a test whit a hydrogen chain. After drawing an H atom at 1Angstrom, 
generate the cell to assure periodicity in one dimension and letting 
enough space in the other two (to avoid interactions as I do for my 
system).
I get a nice plot where the lower energy is a bit higher 
that the value I found  in literature (~-18eV) but the behaviour is as 
expected. However the problems arise if in my unit cell I include two or
 more atoms then I start to see more and more lines (as many as atoms in
 the unit cell) and the energies are all mess-up. 

Is it a normal
 behaviour? I would like to include the pictures but I believe I need to
 send them to the one interested in seeing them.

Then, if I come 
back to my system in which I try to simulate a copolymer (whit 2 units, 2
 times) and two fullerenes, may it means I need to make my unit cell 
smaller or something like that?

Thank you so much in advance.

Best regards: R


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