# Bloch vector setting in bandstructure calculation

I’m studying the band structure calculation using FDTD Solutions recently but is quite confused by the Bloch vector setting in the Triangular 2D example.

Why is the Bloch vector sweeping from gamma to M is 0 to 0.57735?

Hi Jianfeng,

For the coordinates of the k-points in the Brillouin zone we use units of the Bloch vector in the model setup script:

To find out these coordinates you need to consider the shape of the Brillouin zone. For a triangular lattice we have:

After a quick trigonometric calculation you can find that the distance between the Gamma and M points is 1/sqrt(3)= 0.57735 in units of the Bloch vector.

Hope this helps.

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