[Pw_forum] Error from Raman calculation by QE 6.1

[Ilya Ryabinkin]

Raman intensities require polarisation tensor derivatives, which are
formally the third-order properties (mixed (2,1) derivatives wrt E and R),
and program responded:    "third order derivatives not implemented with
GGA".

Minimally, you can enforce LDA calculations instead of an inferred from PP
files PBE (of GGA type), but this is generally not recommended. More
systematic approach is to use LDA-PPs, but you may not be satisfied by LDA
anyway.


On Wed, Jan 10, 2018 at 9:25 PM, jibiaoli <jibiaoli at foxmail.com> wrote:

> Dear All,
>
> I am new to Raman calcualtions and need your help. By using NCPP available
> online, I try to calculate Raman spectra for ZnS, but the following error
> appeared. Is it possible to modify the input to get the Raman spectra? How?
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      task #         4
>      from phq_setup : error #         1
>      third order derivatives not implemented with GGA
>  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> Jibiao Li
> Yangtze Normal University, China
>
> phonon calculation for ZnS
> & inputph
> tr2_ph=1.0d-12,
> prefix='ZnS',
> outdir='./',
> amass(1)=32.066,
> amass(2)=65.409,
> epsil=.true.,
> lraman=.true.,
> trans=.true.,
> fildyn='ZnS_IR.dynG',
> fildrho='ZnS_IR.drho',
> /
> 0.0 0.0 0.0
>
> &CONTROL
> calculation = 'scf',
> prefix = 'ZnS',
> restart_mode = 'from_scratch' ,
> outdir = './' ,
> pseudo_dir   = "/home/bmllzr/codes/pseudo/",
> etot_conv_thr = 1.0d-5 ,
> forc_conv_thr = 1.0d-4 ,
> tstress = .true. ,
> tprnfor = .true. ,
> nstep = 100 ,
> /
> &SYSTEM
> ibrav = 4,
> celldm(1) = 7.1928551712,
> celldm(3) = 1.6400783135,
> nat=4,
> ntyp=2,
> ecutwfc=80,
> /
> &ELECTRONS
> conv_thr = 1.D-12,
> /
> ATOMIC_SPECIES
> S   32.066   S.pbe-hgh.UPF
> Zn  65.409   Zn.pbe-d-hgh.UPF
> ATOMIC_POSITIONS crystal
> S        0.333333333   0.666666667   0.374653315
> S       -0.333333333  -0.666666667   0.874653315
> Zn       0.333333333   0.666666667   0.000346685
> Zn      -0.333333333  -0.666666667   0.500346685
> K_POINTS automatic
> 6 6 6 0 0 0
>
>
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-- 
*******************************************************
                    Ilya Ryabinkin
                 Postdoctoral Scholar
          Physical and Environmental Sciences
           University of Toronto Scarborough
  http://www.utsc.utoronto.ca/~aizmaylov/Members.html
*******************************************************
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