[Wien] volume optimization

[Víctor Luaña Cabal]

On Tue, Dec 13, 2016 at 05:00:01PM +0530, Rajneesh Chaurasiya wrote:
> I have optimised the cubic structure by calculating the total energy with
> varying the lattice parameter size (%). In the optimised file, data has
> been plotted between the total energy and volume of cell. i found that the
> optimized lattice parameter is 8.19 angstrom and corresponding volume of
> cell is 928.34 (a.u3). now if i change the lattice parameter from angstrom
> to atomic unit and calculate the volume then i found 3702 (a.u3) approx. so
> i could not find how the conversion taken place. So can any one suggest
> what types of conversion are happened in the background.

Rajneesh,

1) 3702/928.34 approx 4 (3.9878)
2) The 4 factor agrees with a F structure. The rest is basic crystallography.
3) A cubic structures is not enough information. What cubic? A Pm-3m? A Im-3m?
   A Fm-3m? The three are correct cubic structures (different, of course).

Best,
     Dr. Víctor Luaña
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