How to choose a different band path for band structure calculation using VASP?

Question

How can I set a different band path for VASP calculation? For example I want to plot KGMK but not GMKG for graphene?

Answer 1

You can use a tool called SeeK-path to get the high-symmetry points for your structure using the POSCAR file as an input. For instance, for graphene, your POSCAR could be

C
1.0
1.22800000 -2.12695839  0.00000000
1.22800000  2.12695839  0.00000000
0.00000000  0.00000000  20.
2
direct
   0.00000000  0.00000000  0.25000000
   0.33333333  0.66666667  0.25000000

Then, SeeK-path returns the coordinates for the high-symmetry points, suggests a $\vec{k}$ path, and even provides the suggested path in the KPOINTS-file format for a band-structure calculation with VASP:

Special k-points for band structure
<...>  ! intersections 
line-mode
reciprocal
    0.0000000000     0.0000000000     0.0000000000 1    GAMMA
    0.5000000000     0.0000000000     0.0000000000 1    M 


    0.5000000000     0.0000000000     0.0000000000 1    M 
    0.3333333333     0.3333333333     0.0000000000 1    K 


    0.3333333333     0.3333333333     0.0000000000 1    K 
    0.0000000000     0.0000000000     0.0000000000 1    GAMMA


    0.0000000000     0.0000000000     0.0000000000 1    GAMMA
    0.0000000000     0.0000000000     0.5000000000 1    A 


    0.0000000000     0.0000000000     0.5000000000 1    A 
    0.5000000000     0.0000000000     0.5000000000 1    L 


    0.5000000000     0.0000000000     0.5000000000 1    L 
    0.3333333333     0.3333333333     0.5000000000 1    H 


    0.3333333333     0.3333333333     0.5000000000 1    H 
    0.0000000000     0.0000000000     0.5000000000 1    A 


    0.5000000000     0.0000000000     0.5000000000 1    L 
    0.5000000000     0.0000000000     0.0000000000 1    M 


    0.3333333333     0.3333333333     0.5000000000 1    H 
    0.3333333333     0.3333333333     0.0000000000 1    K 

You can now adjust this file to your preference: Frist, <...> needs to be replaced by the number of $\vec{k}$ points between two high-symmetry points. Second, you can change the $\vec{k}$ path, e.g., by changing the order of the high-symmetry points. For instance, if you want to plot the band structure along K–$\Gamma$–M–K with 3 x 13 $\vec{k}$ points, that yields

K–G–M–K for graphene
13        ! intersections 
line-mode
reciprocal 
    0.3333333333     0.3333333333     0.0000000000 1    K 
    0.0000000000     0.0000000000     0.0000000000 1    GAMMA

    0.0000000000     0.0000000000     0.0000000000 1    GAMMA
    0.5000000000     0.0000000000     0.0000000000 1    M 

    0.5000000000     0.0000000000     0.0000000000 1    M 
    0.3333333333     0.3333333333     0.0000000000 1    K