[Pw_forum] Alpha-Beta-Gamma Angles after a VC-relaxation

[Giuseppe Mattioli]

Dear Francesco

> CELL_PARAMETERS (alat=  9.37304158)
> *_0.998026269_*   0.000004734  -0.013893833
>     0.000009261 _*1.956757114*_ -0.000006827
>    -0.117999199  -0.000006751 *_1.878825464_*

This is a matrix containing the projections of the optimized lattice parameters on the cartesian axes in alat units (alat=9.37304158 bohr). If you 
want your alpha-beta-gamma angles you can calculate them. If you are lazy (I usually am with nonorthogonal cells...) you may open the pw.x output with 
xcrysden and figure out the values with the angle-measurement tool.

HTH
Giuseppe

On Wednesday, May 06, 2015 12:41:09 PM Francesco Pelizza wrote:
> Hi to everyone,
> 
> I am sorry to bother for such a simple question, but I need to be sure
> about what QE is giving me in the OUTPUT file.
> 
> After a VC-relaxation on a cell with angles with one or more of alpha
> beta gamma angles different from 90°, the VC-relaxation OUTPUT file
> gives out this:
> 
> CELL_PARAMETERS (alat=  9.37304158)
> *_0.998026269_*   0.000004734  -0.013893833
>     0.000009261 _*1.956757114*_ -0.000006827
>    -0.117999199  -0.000006751 *_1.878825464_*
> 
> The Bold and underlined values are the new Alat, Blat and Clat factor to
> multiplicate the old alat given, to have the new cell dimension in bohrs.
> 
> But I guess the other numbers are giving me the alpha beta and gamma
> angles (celldm 4-5-6)....
> 
> But who is who?
> 
> Thank you very much for reading!
> 
> Francesco Pelizza

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   Giuseppe Mattioli                            
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
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