band structure

[Poonam Sharma]

dear sir,
I have gotten the band structure output through the file BAND.OUT by setting task 20 in exciting.in file
but it is not clearly understood because range of the band is very small and how shall we recognize the different symmetry points? will u please tell what changes should i make in .in file to get a correct band structure?

  thanks

[exciting]

Hi Poonam,

You have to choose a set of vertices in the Brillouin zone. In the example for silicon (examples/Si/) we have:

plot1d
  7 200                                 : nvp1d, npp1d
  0.0   0.0   1.0                       : vlvp1d
  0.5   0.5   1.0
  0.0   0.0   0.0
  0.5   0.0   0.0
  0.5   0.5   0.0
  0.5   0.25 -0.25
  0.5   0.0   0.0

These correspond to the symbols Gamma, X, Gamma, L, X, W, L.

To help you with this, have a look at the .pdf files in the directory docs/Brillouin. These define the symbol conventions for each crystal symmetry group.

Cheers,
Kay.

[Poonam Sharma]

dear sir,

I have gotten correct band structure  as per your instruction now will you please tell me that which output file should i choose to find the points with which i can denote the symmetry points on the crystal structure?
thanks

[Bultmark]

Look in BANDLINES.OUT