Thank you! It makes much more sense now.
On Tue, May 28, 2013 at 1:47 AM, Axel Kohlmeyer wrote:
> On Tue, May 28, 2013 at 9:57 AM, Yantao Wu wrote:
> > Dear QE,
> >
> > I'm wondering what ibrav means in pw.x. My confusion is that if you can
> > specify atomic positions freely, isn't the struct
On Tue, May 28, 2013 at 9:57 AM, Yantao Wu wrote:
> Dear QE,
>
> I'm wondering what ibrav means in pw.x. My confusion is that if you can
> specify atomic positions freely, isn't the structure of the solid already
> implied by the positions? So why do we need the extra variable of ibrav. Or
> does
Hi Yantao,
A crystal is defined as lattice + basis. A bulk crystal has an infinite
size (infinite is a good approximation for the bulk description) and made
of identical units (which is one unitcell). So you need to know the
geometry of the unitcell (which is lattice) and what is it composed of
(w
Dear QE,
I'm wondering what ibrav means in pw.x. My confusion is that if you can
specify atomic positions freely, isn't the structure of the solid already
implied by the positions? So why do we need the extra variable of ibrav. Or
does ibrav carries more meaning than just the initial lattice struc
