# Re: [Wien] need your help

```Dear Azam
Many excellent books could help you to understand how a band structure works.
I recommend you to look at the following web sites: ```
```
http://www.chem.uci.edu/~lawm/Hoffmann.pdf

calculations to my point of view. Indeed this periodic code is based on k
points. So ... the Gamma point is the center of the Brillouin zone which is in
the reciprocal space, i.e. the space defined by the wave-vectors (k points). It
allows to define Bloch functions which are a product of a molecular orbital
(defined in the unit cell) and a periodic function (dependent on the k point).

The Gamma point is defined by three numbers (0 0 0), meaning kx = 0, ky = 0 and
kz = 0. Indeed, the reciprocal space has three dimension as the real space. In
the case of a cubic symmetry (or orthorhombic) a* = 2.pi / a, b* = 2.pi /b and
c* = 2.pi /c. I will not do all the teaching of the band structure theory but
you can find all these details in books and websites.

Good luck
Xavier

sikander Azam <sikander.physi...@gmail.com> a écrit :

> Dear all
> When we plot the band structure so what the brillion zone symmetry shows
> i.e. lets suppose Gamma point (0 0 0) what this zero shows, these are u v w
> or h k l or x y z.
> regards
> sikander
>```
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