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QuantumATK => General Questions and Answers => Topic started by: Hesam on November 26, 2013, 04:53

Title: Band structure of 4 layers of MoS2 [disables K-M points]
Post by: Hesam on November 26, 2013, 04:53

I can get band structure of mono layer and bilayer MoS2 but when I create 4 mono-layers of MoS2 on top of each other, the high symmetry points like K and M gets disabled in the band structure solver. So how can I get the band structure?

Title: Re: Band structure of 4 layers of MoS2 [disables K-M points]
Post by: zh on November 26, 2013, 08:23

The structure of 4 layers of MoS2 may be created by defining three lattice vectors and calling UnitCell(defined three lattice vectors), e.g.,
vector_a = [1.5802, -2.73699, 0.0]*Angstrom
vector_b = [1.5802, 2.73699, 0.0]*Angstrom
vector_c = [0.0, 0.0, 60.0]*Angstrom
lattice = UnitCell(vector_a, vector_b, vector_c)

You can alternatively define a hexagonal Bravias lattice by calling  Hexagonal(a=xx *Angstrom, c=xxx*Angstrom). e.g.,
lattice = Hexagonal(3.1604*Angstrom, 12.295*Angstrom)
You have to edit the script file and change the definition of lattice.
In this way, you can choose the K and M points in band structure analyser.

Title: Re: Band structure of 4 layers of MoS2 [disables K-M points]
Post by: Hesam on November 27, 2013, 07:09

Thanks for the help. Is it possible to do this through VNL?

Title: Re: Band structure of 4 layers of MoS2 [disables K-M points]
Post by: Anders Blom on November 27, 2013, 09:37

Sure, after you make the repetition just go into Bulk Tools>Lattice Parameters and change the lattice type to Hexagonal, and double-check that nothing weird happened.

In 13.8.1 the repetitions will keep the symmetries of the lattice.

Title: Re: Band structure of 4 layers of MoS2 [disables K-M points]
Post by: Hesam on November 27, 2013, 21:36

Thanks, it worked.