[Pw_forum] Inconsistencies in the CELL_PARAMETERS - ibrav=5

[Stefano de Gironcoli]

sorry but I fail to understand what you are printing ... what is your 
definition for c, tx,ty,tz ... ?
stefano

Marino Vetuschi Zuccolini wrote:
> Hello to all,
>
> I would like to propose to your attention an apparent inconsistency in the matrix of the CELL_PARAMETERS section that I noticed during a relaxation of a crystal with trigonal symmetry (ibrav=5, in attach).
> These inconsistency arise writing few lines in output_tau.f90 to enable the code to print the crystal parameters celldm() for each optimization step.
>
> This is the output of these few lines of code with a simple explanation
>
> ...
> New celldm() values
>
> 1)  celldm(1) =  10.118244326   5.354344288	# new cell edge in bohr and angstrom
> 2)  celldm(4) =   0.647279099			# cos(alpha) solved respect to c in tx
> 3)  |tx|      =   0.419952914   0.419952914	# value of tx as reported in INPUT.PW and in the code
> 						  compared with the element of the matrix at(1,1)
> 4)  |ty|      =   0.242459928   0.242459928	# value of tx as reported in INPUT.PW and in the code
> 						  compared with the element of the matrix at(2,1)
> 5)  |tz|      =   0.874558593  >0.911266395<	# value of tx as reported in INPUT.PW and in the code
> 						  compared with the element of the matrix at(3,1)
> 6)   c_tx     =   0.647279099			# cos(alpha) solved respect to c in tx - redundant with 2)
> 7)   c_ty     =   0.647279099			# cos(alpha) solved respect to c in ty
> 8)   c_tz     =  >0.745609664<			# cos(alpha) solved respect to c in tz
> ...
>
> Points 5) and 8) seem to be not consistent as expected at least by me :)
>
> Please, can someone explain where probably I'm going wrong?
>
> Many thanks to all
>
> m.
>
>   
> ------------------------------------------------------------------------
>
>
>
> *******************************************************
> Marino Vetuschi Zuccolini
> zucco at dipteris.unige.it
> Researcher / Geochemist
> Laboratory of Geochemistry
>
> DIPartimento per lo studio della TErra e delle sue RISorse - Università  di Genova
> Tel. ++39 010 3538136 Fax. ++39 010 352169
> Corso Europa 26, 16132 - Genova - Italy
>
>
>   
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