[Pw_forum] Different Errors of Raman calculations for ZnO and ZnS

[Leonid Kahle]

Dear Jiabao,

regarding the first error, it is self-explaining what happens from the 
error-message that you get: You have to use LDA to compute the Raman 
cross-section, GGA (PBE is a flavor of GGA) is not implemented. You can 
find LDA-pseudos here: http://theossrv1.epfl.ch/Main/Pseudopotentials, 
look for the "pz" in the name.

For the second error, please consider the documentation of the 
phonon-code: 
http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PH.html#idm63
You can't set epsil to true in a metallic system. Analyze the 
occupations in your system, and if you have a sufficient band-gap, turn 
off the smearing for the SCF, and use this new calculation for computing 
the dielectric constant. Also here, you're using PBE for a Raman 
computation, you'd need to switch to LDA.

Best regards,

     Leonid Kahle


On 01/11/2018 07:48 AM, jibiaoli wrote:
> Dear All,
>
> I am using NCPP available online to calculate Raman spectra for ZnS 
> and ZnO, but the two different errors  appeared respectively for the 
> two crystals. Are they highly dependent on crystal structure? How 
> should I modify the inputs and make them working ? Can anyone provide 
> me a working example for Raman spectra?
>
> Error message for ZnS
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      task #         4
>      from phq_setup : error #         1
>      third order derivatives not implemented with GGA
>  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> Error message for ZnO
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      task #         0
>      from phq_readin : error #         1
>      no elec. field with metals
>  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> 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
> ________________________________________________________________________________________
> Normal modes for Wurtzite
>  &inputph
>   tr2_ph=1.0d-14,
>   prefix='ZNO',
>   outdir='./',
>   amass(1)=65.409,
>   amass(2)=15.999,
>   epsil=.true.,
>   lraman=.true.
>   trans=.true.,
>   asr=.true.
>   fildyn='dmat.zno'
>  /
>  0.0 0.0 0.0
>
> &CONTROL
>   calculation  = "scf",
>   prefix       = "ZNO",
>   pseudo_dir   = "/home/bmllzr/codes/pseudo/",
>   outdir       = "./",
> /
> &SYSTEM
>   ibrav=0, celldm(1) =6.330582528, nat=4, ntyp= 2,
>   occupations='smearing', smearing='marzari-vanderbilt', degauss=0.02,
>   ecutwfc =80.0, !better 140
> /
> &ELECTRONS
>   mixing_mode='plain'
>   mixing_beta = 0.5,
>   startingwfc='random',
>   conv_thr =  1.0d-8
> /
> CELL_PARAMETERS alat
>   1.55820896     0.00000000     0.00000000
>   0.00000000     0.86602540     -0.50000000
>   0.00000000     0.00000000     1.00000000
> ATOMIC_SPECIES
>   Zn 65.409  Zn.pbe-d-hgh.UPF
>   O  15.999  O.pbe-hgh.UPF
> ATOMIC_POSITIONS (alat)
> Zn       2.010975287   0.487933254  -0.051360548
> Zn       1.234717421   0.199473387   0.448322227
> O        1.051679030   0.488287222  -0.051814333
> O        1.830251369   0.199830262   0.448810714
> K_POINTS (automatic)
> 2 2 2 0 0 0
>
>
>
>
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