My Community

Hello,

I would like to calculate the Density of States of a 1D structure,
To do that I use for example a KPOINTS file (for relaxation and static calculation),

*******************
KPOINTS
*******************

Automatic
0
Gamma
1 x 1
0 0 0

(Where x is a number and depends on calculations)

*******************

Moreover, I let my structures relaxed up to the forces acting on each atoms decrease below 0.005 eV/atom.

The problem is that :
For static calculation and non self-consistent calculation,
the smearing method (ISMEAR = -5) gives me a wrong Fermi level but well describes the typical peaks of 1D structure when I plot the DOS.

If I use ISMEAR = 0, the Fermi level is well described but the plot of DOS is not good at all, even if I increase NEDOS up to 1000 (or more) over a region (in energy) centered around the Fermi level

My questions are:

- Does it exist a compromise between the two methods?
- Is it possible to calculate accurate DOS for 1D structures using ISMEAR = -5 ?
If yes, which k-points mesh is the more suited to do that ?

- Using ISMEAR = 0, is it possible to get accurate DOS (with the k-points mesh described above)?

Kind regards,

Damien

for 1D (linear) structures, please use a k-mesh aprropriate for systems having 1D translational symmetry ONLY, i.e. an Nx1x1 k-mesh for SCF and DOS runs and Gaussian BZ integration.