[Pw_forum] Dielectric constant at RPA level with PHONON

[Vahid Askarpour]

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