[Pw_forum] Dielectric constant at RPA level with PHONON

[stefano de gironcoli]

because somewhere in phq_readin
    trans = trans .OR. ldisp
lrpa is only valid for the calculation of the macroscopic dielectric 
constant, not for the vibrational parts.

stefano

On 30/06/2017 01:06, Vahid Askarpour wrote:
> Dear QE Users,
>
> After a self consistent calculation, I used the following input to the ph.x code (qe-6.1) to calculate the dielectric constant at the RPA level using the lrpa tag.
>
> SnSe
> &inputph
>    tr2_ph   =  1.0d-16
>    prefix   = 'SnSe'
>    amass(1) = 118.71
>    amass(2) = 78.96
>    ldisp = .true.
>    epsil=.true.
>    trans = .false.
>    lrpa = .true.
>    qplot = .true.
>    outdir   = './'
>    alpha_mix(1)=0.3
>    fildyn   = 'SnSe.dyn'
>    fildvscf = 'dvscf'
>   /
>   48
>             0.0000000   0.0000000   0.0000000   0.0138889
>             0.0000000   0.0000000   0.1666667   0.0277778
>             0.0000000   0.0000000   0.3333333   0.0277778
>             0.0000000   0.0000000  -0.5000000   0.0138889
>             0.0000000   0.1666667   0.0000000   0.0277778
>             0.0000000   0.1666667   0.1666667   0.0555556
>             0.0000000   0.1666667   0.3333333   0.0555556
>             0.0000000   0.1666667  -0.5000000   0.0277778
>             0.0000000   0.3333333   0.0000000   0.0277778
>             0.0000000   0.3333333   0.1666667   0.0555556
>             0.0000000   0.3333333   0.3333333   0.0555556
>             0.0000000   0.3333333  -0.5000000   0.0277778
>             0.0000000  -0.5000000   0.0000000   0.0138889
>             0.0000000  -0.5000000   0.1666667   0.0277778
>             0.0000000  -0.5000000   0.3333333   0.0277778
>             0.0000000  -0.5000000  -0.5000000   0.0138889
>             0.2500000   0.0000000   0.0000000   0.0277778
>             0.2500000   0.0000000   0.1666667   0.0555556
>             0.2500000   0.0000000   0.3333333   0.0555556
>             0.2500000   0.0000000  -0.5000000   0.0277778
>             0.2500000   0.1666667   0.0000000   0.0555556
>             0.2500000   0.1666667   0.1666667   0.1111111
>             0.2500000   0.1666667   0.3333333   0.1111111
>             0.2500000   0.1666667  -0.5000000   0.0555556
>             0.2500000   0.3333333   0.0000000   0.0555556
>             0.2500000   0.3333333   0.1666667   0.1111111
>             0.2500000   0.3333333   0.3333333   0.1111111
>             0.2500000   0.3333333  -0.5000000   0.0555556
>             0.2500000  -0.5000000   0.0000000   0.0277778
>             0.2500000  -0.5000000   0.1666667   0.0555556
>             0.2500000  -0.5000000   0.3333333   0.0555556
>             0.2500000  -0.5000000  -0.5000000   0.0277778
>            -0.5000000   0.0000000   0.0000000   0.0138889
>            -0.5000000   0.0000000   0.1666667   0.0277778
>            -0.5000000   0.0000000   0.3333333   0.0277778
>            -0.5000000   0.0000000  -0.5000000   0.0138889
>            -0.5000000   0.1666667   0.0000000   0.0277778
>            -0.5000000   0.1666667   0.1666667   0.0555556
>            -0.5000000   0.1666667   0.3333333   0.0555556
>            -0.5000000   0.1666667  -0.5000000   0.0277778
>            -0.5000000   0.3333333   0.0000000   0.0277778
>            -0.5000000   0.3333333   0.1666667   0.0555556
>            -0.5000000   0.3333333   0.3333333   0.0555556
>            -0.5000000   0.3333333  -0.5000000   0.0277778
>            -0.5000000  -0.5000000   0.0000000   0.0138889
>            -0.5000000  -0.5000000   0.1666667   0.0277778
>            -0.5000000  -0.5000000   0.3333333   0.0277778
>            -0.5000000  -0.5000000  -0.5000000   0.0138889
>
> I get the following error:
>
>   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
>       task #         6      from phq_readin : error #         1
>       only dielectric constant with lrpa or lnoloc
>   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> I checked the phq_redin.f90 code and the error arises from the following line:
>
>    IF (trans.AND.(lrpa.OR.lnoloc)) CALL errore('phq_readin', &
>                      'only dielectric constant with lrpa or lnoloc',1)
>
> Since I have set trans=.false., why am I getting this error? There must be something wrong with the input but no such error was reported to the Forum.
>
> Any suggestions would be appreciated.
>
> Thank you,
>
> Vahid
>
> Vahid Askarpour
> Department of Physics and Atmospheric Science
> Dalhousie University,
> Halifax, NS, Canada
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