Re: define bock

On Mar 26, 2008, at 10:36 AM, andika asyuda wrote:
> I try to define triangular lattice structure by MPB, with block as  
> basis
> but I do not now how to get the usual block. When I define e1,e2,e3  
> like following
>
> (e1 0.5 0.5 0) (e2 0.866 -0.866 0)
>
> I get thee rotated block rather than usual block.

The e1/e2/e3 vectors are given in the lattice basis like most other  
vectors, resulting in skewed blocks for a triangular lattice.  If you  
want to specify them in Cartesian coordinates, you can use cartesian- 
 >lattice, e.g. (e1 (cartesian->lattice (vector3 0.5 0.5 0)))

> Another thing I want to know is, if there is a way  in MPB  to get   
> the  k-point  of  band  calculation  in  x-y  basis,  not   
> reciprocal  lattice  basis.This is a problem when I try to get EFS

Use reciprocal->cartesian.  e.g. (print (map reciprocal->cartesian k- 
points) "\n") while print out all the k-points in Cartesian  
coordinates (divided by 2pi).

Steven