[Wien] Cohesive energies in WIEN2k

[Peter Blaha]

> >   (4) Finally, why should the single atom at the origin be placed in
> > an FCC  lattice 
> >   and not a Simple Cubic lattice say ? In other words why FCC and not
> > some 
> >   other lattice.
> 
> I admit I do not get that point either, although I suspect it to be
> simple. I would think that for a given lattice constant the interatomic
> separation is largest in simple cubic?

The point is: fcc is a "close packed lattice", thus for a given 
"nn-distance" (not lattice parameter, which you will adjust to get the 
desired nn-distance) you will get the smallest "volume" 
of the unit cell and thus the most economical calculation.


                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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