[Pw_forum] Generating K points for Wurzite Structure using crystal_b

[Ari P Seitsonen]

Dear Mustapha,

   Adding to the comment of M V Kondrin, some comments: I also do not 
understand why you no longer have the exact hexagonal symmetry laterally; 
further, ecutrho => 4 * ecutwfc, otherwise you might get some nasty 
effects (your input does not reveal which pseudo potentials/PAW data sets 
you were employing); why using the cold smearing if the system would 
probably be semi-conducting or even insulating; and the k point with high 
symmetry would actually be (1/3,1/3,0), not (0.3,0.3,0).

     Greetings from Paris,

        apsi

-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
   Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
     Ecole Normale Supérieure (ENS), Département de Chimie, Paris
     Mobile (F) : +33 789 37 24 25    (CH) : +41 79 71 90 935


On Thu, 31 Mar 2016, lateef mustapha wrote:

> Dear QE Users, I just successfully generated the k points for plotting the band structure of a wurzite structure. The crystal direction of the calculated are approximated and I guess that was the reason why my band dispersion were fairly distorted. Any advice ?
> see Input file below
>
> Reading   16 bands at     91 k-points
> Range:   -9.1640   28.7880eV  Emin, Emax > -9.164 28.788
> high-symmetry point:  0.0000 0.0000 0.0000   x coordinate   0.0000
> high-symmetry point:  0.0000 0.0000 0.3019   x coordinate   0.3019
> high-symmetry point:  0.4993 0.2883 0.3019   x coordinate   0.8784
> high-symmetry point:  0.4993 0.2883 0.0000   x coordinate   1.1803
> high-symmetry point:  0.0000 0.0000 0.0000   x coordinate   1.7569
> high-symmetry point:  0.2996 0.5189 0.0000   x coordinate   2.3561
> high-symmetry point:  0.2996 0.5189 0.3019   x coordinate   2.6580
>
> &CONTROL
>    restart_mode = 'from_scratch'
>    tstress = .TRUE.,
>    tprnfor = .TRUE. ,
>    calculation = 'bands'
>    pseudo_dir  = '/home/musty/esp/pseudo/PW91'
>    prefix = 'BN'
> /
> &SYSTEM
>    ibrav =  4,
>    celldm(1) = 4.82,
>    celldm(3) = 1.65,
>    occupations='smearing' ,
>    smearing='mp',
>    nat =  4,
>    ntyp = 2,
>    nbnd = 16,
>    degauss=0.06,
>    ecutwfc = 65,
>    ecutrho = 200,
> /
> &ELECTRONS
>    diagonalization='david'
>    mixing_mode = 'plain'
>    mixing_beta = 0.7
>    conv_thr =  1.0d-8
> /
> ATOMIC_SPECIES
> B  10.811
> N  14.001
>
> CELL_PARAMETERS (alat=  4.82000000)
>   1.001361289   0.000000000   0.000000000
>  -0.500680645   0.867204315   0.000000000
>   0.000000000   0.000000000   1.656271159
>
> ATOMIC_POSITIONS (crystal)
> B        0.000000000   0.000000000   0.000317468
> B        0.666666700   0.333333300   0.500317468
> N        0.000000000   0.000000000   0.374682532
> N        0.666666700   0.333333300   0.874682532
>
> K_POINTS crystal_b
> 7
> 0.0 0.0 0.0 10
> 0.0 0.0 0.5 20
> 0.5 0.0 0.5 10
> 0.5 0.0 0.0 20
> 0.0 0.0 0.0 20
> 0.3 0.3 0.0 10
> 0.3 0.3 0.5 1
>
> Mustapha L.O
> Graduate Student, University of Ibadan. Nigeria
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>