[Pw_forum] nqx in HSE

[Amin Torabi]

Thanks, but do you have any suggestion for my input file?


On Fri, Nov 23, 2012 at 4:22 PM, Amin Torabi <mtorabi at uwo.ca> wrote:

> Dear all,
>
> Using the following input file, I am trying to reproduce the bandgap of
> ZnS (wurtzite). The structure is optimized (vc-relax at 1 atm) employing
> PBEsol, and now I am using HSE to do scf.
>
> Question:
> using nqx1=nqx2=nqx3=1,  I found the bandgap to be 3.66 eV, which is
> comparable to others (PRL 102, 226401 (2009); however, by using nqx1=nqx2=3
> and nqx3=2, the bandgap is reduced to 3.24ev.
>
> Does denser auxiliary mesh not mean an improved calculation?
> I would appreciate any comment on my input file?
> Thanks!
>
>
>
> &CONTROL
>          calculation     = 'scf'
>         prefix          = 'ZnS'
>         pseudo_dir      = '...'
>         outdir          = '...'
> /
> &SYSTEM
>         ibrav            = 0
>         celldm(1)      = 7.20174629
>         nat               = 4
>         ntyp             = 2
>         nbnd            = 20
>         ecutwfc        = 110
>         nqx1            = 1
>         nqx2            = 1
>         nqx3            = 1
>         input_dft       = 'hse'
>         x_gamma_extrapolation = .true
>         exxdiv_treatment='gygi-baldereschi'
> /
> &ELECTRONS
>         conv_thr        = 1.0D-7
> /
> ATOMIC_SPECIES
>  Zn 65.409  Zn.pbe-nc.UPF
>  S  32.066  S.pbe-n-nc.UPF
> CELL_PARAMETERS (alat=  7.20174629)
>    0.992513482   0.000001434   0.000000000
>   -0.496255499   0.859542606   0.000000000
>    0.000000000   0.000000000   1.628169588
> ATOMIC_POSITIONS (crystal)
> Zn       0.333333038   0.666666962   0.000366211
> Zn       0.666666962   0.333333038   0.500366148
> S        0.333333175   0.666666825   0.374633891
> S        0.666666825   0.333333175   0.874633750
> K_POINTS automatic
>  6 6 4 0 0 0
>
>
> --
> ***************************************
> Amin Torabi
> Ph.D. Student
> Chemistry Dept.
> Western University
> London, On Canada, N6A 5B7
> Phone: 519-661-2111 Ext: 87871
> ****************************************
>
>


-- 
***************************************
Amin Torabi
Ph.D. Student
Chemistry Dept.
Western University
London, On Canada, N6A 5B7
Phone: 519-661-2111 Ext: 87871
****************************************
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