How choose k-points for 5*5*4 slab for band gap calculations

In summary, the appropriate k-points for a 5*5*4 slab for band gap calculations can be determined using methods such as the Monkhorst-Pack or Gamma-centered method. Selecting the right k-points is important for accurate results, as insufficient or excessive k-points can affect convergence. A convergence test can be performed to determine if the selected k-points are sufficient. There are general guidelines for choosing k-points based on the type of material being studied, and the k-point sampling should be adjusted for different orientations of the same slab.
  • #1
vino
3
0
Is there any method for how to choose k-points in band structure calculations for aluminium slab 5*5*4
can somebody help in this question?

Thanks
 
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  • #3
Dr Transport said:
what do you mean by 5*5*4 slab?
Four layer surface with 5 atoms in x-direction and 5 atoms in y-direction
 

1. How do I determine the appropriate k-points for a 5*5*4 slab for band gap calculations?

The appropriate k-points for a 5*5*4 slab for band gap calculations can be determined by using a k-point sampling method such as the Monkhorst-Pack method or the Gamma-centered method. These methods take into account the size and symmetry of the slab to generate a set of k-points that adequately sample the Brillouin zone.

2. What is the significance of choosing the right k-points for band gap calculations?

Choosing the right k-points is crucial for accurate band gap calculations as it affects the convergence of the results. Insufficient k-points can result in an underestimation of the band gap, while an excessive number of k-points can lead to computational inefficiency.

3. How can I determine if the selected k-points are sufficient for my band gap calculations?

A good way to determine if the selected k-points are sufficient is by performing a convergence test. This involves running the calculation with increasing numbers of k-points and comparing the resulting band gap values. Once the values converge to a stable range, the k-point sampling can be considered sufficient.

4. Are there any guidelines for choosing k-points for specific materials in band gap calculations?

Yes, there are general guidelines for choosing k-points based on the type of material being studied. For example, for semiconductors, the k-point sampling should be dense enough to accurately capture the band edges, while for metals, a coarser sampling can be used.

5. Can I use the same k-point sampling for different orientations of the same slab in band gap calculations?

No, the k-point sampling should be adjusted for different orientations of the same slab to accurately capture the electronic structure. This is because the symmetry and size of the Brillouin zone may vary for different orientations, therefore requiring a different set of k-points.

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