Re: Selecting all the relevant k-points

On Jan 16, 2009, at 3:33 PM, Ian D. Hosein wrote:
>    I'm trying now to determine the k-points I would have to  
> interpolate.
> For example, I know I would have the interpolate points betwen A to  
> B and B
> to C, or G to J or S to M. However, would I also need to interpolate
> between, say, E and G or D and K (i..e diagonal across faces and the  
> like)?
>    I'm trying to look for general principles to choose all the points
> necessary (minimizing redundancies and unneccessary points) for  
> which to do
> calcuations to create my band structure.

In general, you have to look at all the points over the whole  
irreducible Brillouin zone, including the interior.

In a symmetric structure, you can show that the boundaries of the IBZ  
are at least local extrema of the bands, and because of this the  
global extrema tend to occur at the boundaries too, but there is no  
guarantee.

When I'm searching for gaps, I usually just look at some more-or-less  
randomly selected edges along the boundaries.  But if you find a new  
structure that you care about, to be thorough you should check the  
interior of the IBZ too.

Steven