[Wien] Re Re: integer elements in rotation operation

[Peter Blaha]

> However, I probably think that you misunderstood you question.
> 
> My questions can be expressed as foloowings:
> 
> 1) whether the basis vectors of the coordinate system on which the rotation operation act
>    are unit cell or primary cell basis, which may be not orthogonal to each other.

As I mentioned, this depends on the specific lattice. Eg. for an
F-centered structure, the "conventional" (cubic) cell is used as
coordinate system, while for eg. a hex. lattice, the hexagonal basis
will be used.


> 2) for two vectors whose coordinates are expressed in non-orthogonal basis, the dot-product operation
> 
>    between them will not be directly implemented as the dot-product operation of two vectors whose coordintes 
> 
>   are expressed in orthogonal system. I think that at least one should first convert the coordinats of 
> 
>    non-orthogonal systm  to the corresponding coordinates in orthogonal system, then dot-product 
> 
>    operation will be carried out as usually.i.e (x1i+y1j+z1k).dot.(x2i+y2j+z2k)=x1*x2+y1*y2+z1*z2
> 
> but thoroughly this conversion step is not found in stern.f 
> 
> so, what is goning on here about the basis vectors choosing techniques ?

A dot product K.R is independent on the chosen coordinate system (as
long as both K and R space are corresponding to the same system).