Density of states

[serhan]

I'd like to ask how can we calculate the density of states and plot it for carbon nanotubes in ATK? We have *.nc files of the simulations of various metallic CNTs (two-probe simulations). How can we extract DOS from these *.nc files?

Cheers,
Serhan

[zh]

To know how to calculate the DOS using ATK, you may refer to the tutorials demonstrated here:
http://quantumwise.com/tutorials
http://quantumwise.com/documents/tutorials/bulk_dos.py

The data for DOS is not stored in the '.nc' files, so they can not be extracted. You may use "ncdump" tool of NetCDF to see what are stored in the '.nc' file.

[serhan]

Hi, Thanks for your reply. However, the tutorial writes: "The method used for the DOS calculation is the tetrahedron method, suitable for real 3D crystal. The provided script is, as the name indicates, not suitable for 1D or 2D systems like nanotubes or graphene." We need to calculate the DOS of CNT, a 1-D structure. Also, the tutorial has an example:

Code

from ATK.KohnSham import *
from bulk_dos import *
# Specify checkpoint file here!
scf = restoreSelfConsistentCalculation('c:/vnl/au.nc')
dos = calculateDensityOfStates(scf, -5*eV, 5*eV, 100, accuracy=4)
dos.plot('c:/vnl/au_dos.png')

From this I understand that the DOS can be extracted from scf included in *.nc files. Cheers, Serhan

[zh]

For the DOS calculations, it has been discussed many times in this forum, e.g., see the topic here:
http://quantumwise.com/forum/index.php?topic=261.0

[serhan]

Thanks, it's now Ok.

Cheers
Serhan