[Pw_forum] choosing k-point in slab calculations

[David Foster]

Dear Users

Suppose, we have constructed a metallic surface and a vacuum slab with some thickness.

Normally, these super-cells have no symmetry. My main question is that how we should 

choose the k-point? Only in the surface or we can choose some points in the inner layers

or even vacuum near to the surface?



PS: I have calculated band structure for the plane parallel to the surface but in the middle 

point of the vacuum (far from the surface). I expected that I didn't get any band graphs; however,

I got some. Can anybody tell me why? 



Regards

David Foster

Ph.D. Student of Chemistry