If you are using v.7.4.1 and later, please see this:
https://gitlab.com/QEF/q-e/-/merge_requests/2715
Paolo
On 11/5/2025 4:27 PM, Shubham Patel via users wrote:
Dear Quantum Espresso users,
I am doing phonon calculations to calculate the dielectric constant and Raman
spectra, but in the output I am getting the dielectric constant in form of
'*****', is it because the value is too large?
More specifically, is it true that calculating Raman spectra for metals is not
implemented in Quantum Espresso. How does that work in VASP (for metals)?
###########################################
iter # 30 total cpu time : 130.1 secs av.it.: 21.3
thresh= 6.211E-10 alpha_mix = 0.700 |ddv_scf|^2 = 1.347E-18
iter # 31 total cpu time : 134.9 secs av.it.: 22.7
thresh= 1.161E-10 alpha_mix = 0.700 |ddv_scf|^2 = 5.013E-19
End of electric fields calculation
Dielectric constant in cartesian axis
(****************** -0.381280124 0.000000000 )
( 0.381280154****************** 0.000000000 )
( 0.000000000 0.000000000 -284.777139614 )
##########################################################
Also, there is this scf cycle for dv_scf, the value of which is keep increasing.
#######################################################
Derivative coefficient: 0.001000 Threshold: 1.00E-12
kpoint 1 ibnd**** pcgreen: root not converged 2.723E-08
kpoint 1 ibnd**** pcgreen: root not converged 2.007E-09
kpoint 1 ibnd**** pcgreen: root not converged 8.698E-09
kpoint 1 ibnd**** pcgreen: root not converged 9.726E-11
kpoint 1 ibnd**** pcgreen: root not converged 5.332E-11
kpoint 1 ibnd**** pcgreen: root not converged 1.593E-12
kpoint 1 ibnd**** pcgreen: root not converged 1.676E-12
kpoint 1 ibnd**** pcgreen: root not converged 1.638E-12
kpoint 1 ibnd**** pcgreen: root not converged 1.803E-12
Non-scf u_k: avg # of iterations = 33.0
Non-scf Du_k: avg # of iterations = 71.8
Dielectric constant from finite-differences
(****************** -0.000005722 0.000000000 )
( -0.000003815****************** 0.000000000 )
( -0.000000000 -0.000000000 -31779.441608902 )
Computing Second order response
kpoint 1 ibnd**** pcgreen: root not converged 3.031E+01
kpoint 1 ibnd**** pcgreen: root not converged 6.080E+01
kpoint 1 ibnd**** pcgreen: root not converged 6.610E+01
iter # 1 av.it.: 65.3
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 1.221E+30
kpoint 1 ibnd**** pcgreen: root not converged 2.161E+07
kpoint 1 ibnd**** pcgreen: root not converged 2.800E+06
kpoint 1 ibnd**** pcgreen: root not converged 9.143E+06
iter # 2 av.it.: 82.3
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 2.786E+39
kpoint 1 ibnd**** pcgreen: root not converged 2.487E+08
kpoint 1 ibnd**** pcgreen: root not converged 1.773E+10
kpoint 1 ibnd**** pcgreen: root not converged 1.710E+09
iter # 3 av.it.: 74.0
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 6.365E+40
kpoint 1 ibnd**** pcgreen: root not converged 2.377E+08
kpoint 1 ibnd**** pcgreen: root not converged 1.246E+08
kpoint 1 ibnd**** pcgreen: root not converged 1.434E+08
iter # 4 av.it.: 89.0
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 4.085E+41
kpoint 1 ibnd**** pcgreen: root not converged 6.110E+07
kpoint 1 ibnd**** pcgreen: root not converged 4.883E+08
kpoint 1 ibnd**** pcgreen: root not converged 5.098E+07
iter # 5 av.it.: 81.7
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 3.790E+41
...
################################################
Here is my input for the ph.x
&inputph
tr2_ph=1.0d-18,
prefix='conbse',
amass(2)= 92.90638,
amass(3)= 78.96,
outdir='./out/',
fildyn='conbse.dynG',
lraman=.true.,
epsil=.true.,
trans=.true.,
asr=.true.
/
0.0 0.0 0.0
Could somebody tell me why this cycle for dv_scf which increases infinitely? I
am doing a Gamma point calculation for pw.x and ph.x.
Thank you for your time.
Sincerely,
Shubham
_______________________________________________________________________________
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worldwide who are victims of terrorism, military aggression, and indiscriminate
warfare.
--------------------------------------------------------------------------------
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
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--
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216
_______________________________________________________________________________
The Quantum ESPRESSO Foundation stands in solidarity with all civilians
worldwide who are victims of terrorism, military aggression, and indiscriminate
warfare.
--------------------------------------------------------------------------------
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
