[Pw_forum] input structure for ibrav=9

[Paolo Giannozzi]

On Nov 28, 2011, at 15:19 , Amin Torabi wrote:

> How come V1 and V2 are not orthogonal?

why should they be orthogonal? The three basis vectors are orthogonal
only for simple orthorhombic.

> And do I have to express the fractional atomic position in terms of  
> A,B,C
> or V1, V2 and V3?

this is something that you have to know. Atomic positions are sometimes
given as cartesian coordinates, sometimes as fractional coordinates
xV_1 + yV_2 + yV_3. Of course the values of x,y,z may depend upon
the choice of V_1, V_2, V_3

P.
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Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222