[QE-users] phonon linewidth calculation
Ivan Dario Arellano Ramirez
arellano at utp.edu.co
Wed Jun 11 01:35:05 CEST 2025
In my initial calculation, I set occupations='fixed', but the ph.x module
immediately returned the error: *"Electron-phonon only for metals."* That's
why I attempted to use ocuppations='smearing' with a small degauss value,
even though InN is a semiconductor. This raises the question: Is it in
fact only possible to calculate phonon linewidth just for metalic systems?
El mar, 10 jun 2025 a las 2:14, Lorenzo Paulatto (<lorenzo.paulatto at cnrs.fr>)
escribió:
> I notice now that you have a ridiculous E_Fermi shift of 550 Ry, is your
> material by any chance an insulator, but you are using
> occupation='smearing'? If you have a gap, you must use occupation='fixed'
> in phonon. If you want to have magnetization, you will have to specify in
> pw input the total magnetization.
>
> hth
> On 09/06/2025 11:05, Ivan Dario Arellano Ramirez wrote:
>
> Dear Lorenzo,
>
> I tried the settings you suggested:
>
> nmix_ph=10
> alpha_mix=.25
>
> and conv_thr = 1.0d-12 for scf calculation
>
> however, the phonon calculation using ph.x still fails to converge.
>
> I then increased the nmix_ph up to 20 and decreased the alpha_mix up to
> .1 but the issue persists.
>
> El sáb, 7 jun 2025 a las 7:14, Lorenzo Paulatto (<lorenzo.paulatto at cnrs.fr>)
> escribió:
>
>> Hhelo,
>>
>> increase nmix_ph and reduce alpha_mix, in a difficult case recently I
>> have used:
>>
>> nmix_ph=10
>> alpha_mix=.25
>>
>> Also, the convergence of the scf process in pw.x should be tighter,
>> something like
>> conv_thr = 1.0d-12
>>
>> Because the total energy is variational, but the phonons are not, they
>> converge much slower with this threshold.
>>
>> hth
>>
>>
>>
>> On 06/06/2025 21:48, Ivan Dario Arellano Ramirez wrote:
>>
>> I QE users
>>
>> I want to calculate the phonon linewidth for InN. I am following two
>> tutorials. However, in both cases, I encounter the same issue: no
>> convergence when using the ph.x module.
>>
>> Pert. # 1: Fermi energy shift (Ry) = -5.5393E+02 0.0000E+00
>>
>> iter # 150 total cpu time : 13815.8 secs av.it.: 5.3
>> thresh= 4.679E-04 alpha_mix = 0.700 |ddv_scf|^2 = 4.318E-06
>>
>> End of self-consistent calculation
>>
>> No convergence has been achieved
>>
>>
>> This is an overview of the two approaches I followed:
>>
>> 1) perform very dense scf calculation with la2F=.true. in &systems
>> (Likely, I am exceeding the maximum of 40000 k points)
>> 2) normal scf on coarser k-mesh
>> 3) phonon calculation using ph.x
>> 4) Inverse Fourier transform of dynamical matrix and the phonon linewidth
>> using q2r.x
>> 5) Fourier transform to obtain dynamical matrix and the phonon linewidth
>> using matdyn.x
>>
>> The other tutorial proposed an initial scf calculation followed by an
>> nscf calculation with la2F=.true. the rest of steps are the same.
>>
>> Here are all the inputs.
>>
>> Any suggestions or insights would be greatly appreciated.
>>
>>
>> 1) very dense k-mesh scf
>>
>> &control
>> calculation = 'scf'
>> restart_mode='from_scratch',
>> prefix='inn_ep',
>> tstress = .true.
>> tprnfor = .true.
>> pseudo_dir = '/home/pps/pbe.0.3.1/PSEUDOPOTENTIALS/',
>> outdir='./tmp'
>> verbosity = 'high'
>> etot_conv_thr = 1.d-6
>> forc_conv_thr = 1.d-5
>> /
>> &system
>> ibrav = 0,
>> nat= 4,
>> ntyp= 2,
>> ecutwfc = 90,
>> ecutrho = 900,
>> occupations='smearing',
>> smearing='m-v',
>> degauss=0.02,
>> la2F = .true.
>> /
>> &electrons
>> conv_thr = 1.0d-8
>> electron_maxstep = 200,
>> mixing_mode = 'plain'
>> mixing_beta = 0.3D0
>> diagonalization = 'david'
>> /
>> ATOMIC_SPECIES
>> In 114.818 In.pbe-dn-rrkjus_psl.1.0.0.UPF
>> N 14.007 N.pbe-n-rrkjus_psl.1.0.0.UPF
>> CELL_PARAMETERS angstrom
>> 1.793358573 -3.106188164 0.000000000
>> 1.793358573 3.106188164 0.000000000
>> 0.000000000 0.000000000 5.799337066
>>
>> ATOMIC_POSITIONS crystal
>> In 0.3333330000 0.6666670000 -0.0019331848
>> In 0.6666670000 0.3333330000 0.4980668152
>> N 0.3333330000 0.6666670000 0.3767331848
>> N 0.6666670000 0.3333330000 0.8767331848
>> K_POINTS automatic
>> 45 45 36 0 0 0
>>
>> 2) normal scf
>>
>> &control
>> calculation = 'scf'
>> restart_mode='from_scratch',
>> prefix='inn_ep',
>> tstress = .true.
>> tprnfor = .true.
>> pseudo_dir = '/home/pps/pbe.0.3.1/PSEUDOPOTENTIALS/',
>> outdir='./tmp'
>> verbosity = 'high'
>> etot_conv_thr = 1.d-6
>> forc_conv_thr = 1.d-5
>> /
>> &system
>> ibrav = 0,
>> nat= 4,
>> ntyp= 2,
>> ecutwfc = 90,
>> ecutrho = 900,
>> occupations='smearing',
>> smearing='m-v',
>> degauss=0.02,
>> /
>> &electrons
>> conv_thr = 1.0d-8
>> electron_maxstep = 200,
>> mixing_mode = 'plain'
>> mixing_beta = 0.3D0
>> diagonalization = 'david'
>> /
>> ATOMIC_SPECIES
>> In 114.818 In.pbe-dn-rrkjus_psl.1.0.0.UPF
>> N 14.007 N.pbe-n-rrkjus_psl.1.0.0.UPF
>> CELL_PARAMETERS angstrom
>> 1.793358573 -3.106188164 0.000000000
>> 1.793358573 3.106188164 0.000000000
>> 0.000000000 0.000000000 5.799337066
>>
>> ATOMIC_POSITIONS crystal
>> In 0.3333330000 0.6666670000 -0.0019331848
>> In 0.6666670000 0.3333330000 0.4980668152
>> N 0.3333330000 0.6666670000 0.3767331848
>> N 0.6666670000 0.3333330000 0.8767331848
>> K_POINTS automatic
>> 15 15 12 0 0 0
>>
>> 3) phonon calculation
>>
>> Phonons of InN at G!=0
>> &inputph
>> tr2_ph = 1.0d-14,
>> ldisp = .true.,
>> prefix = 'inn_ep',
>> recover = .true.
>> fildyn = 'inn-ph.dyn',
>> fildvscf = 'inndv'
>> nq1 = 5,
>> nq2 = 5,
>> nq3 = 3,
>> electron_phonon = 'interpolated'
>> el_ph_nsigma = 10
>> el_ph_sigma = 0.02
>> amass(1) = 114.818,
>> amass(2) = 14.007,
>> outdir = './tmp'
>> /
>>
>> 4) Inverse Fourier Transform
>>
>> &INPUT
>> fildyn = 'inn-ph.dyn',
>> zasr = 'crystal',
>> flfrc = 'inn-ph.fc',
>> la2F = .true.
>> /
>>
>> 5) Fourier Transform
>>
>> &input
>> asr = 'crystal',
>> flfrc = 'inn-ph.fc',
>> flfrq = 'inn.band.freq'
>> flvec = 'inn.band.modes'
>> amass(1) = 114.818,
>> amass(2) = 14.007,
>> q_in_band_form = .true.
>> la2F = .true.
>> /
>> 8
>> 0.0000000000 0.0000000000 0.0000000000 40 ! Gamma
>> 0.5000000000 0.0000000000 0.0000000000 25 ! M
>> 0.3333333333 0.3333333333 0.0000000000 40 ! K
>> 0.0000000000 0.0000000000 0.0000000000 25 ! Gamma
>> 0.0000000000 0.0000000000 0.5000000000 40 ! A
>> 0.5000000000 0.0000000000 0.5000000000 25 ! L
>> 0.3333333333 0.3333333333 0.5000000000 40 ! H
>> 0.0000000000 0.0000000000 0.5000000000 1 ! A
>>
>>
>> Best regards,
>>
>> --
>>
>> Iván Darío Arellano Ramírez
>>
>> Profesor Titular Programa de Ingeniería Física
>>
>> Director Grupo de Investigación en Modelado y Simulación Computacional
>>
>> Universidad Tecnológica de Pereira
>>
>> El contenido de este mensaje y sus anexos son únicamente para el uso del
>> destinatario y pueden contener información clasificada o reservada. Si
>> usted no es el destinatario intencional, absténgase de cualquier uso,
>> difusión, distribución o copia de esta comunicación.
>>
>> _______________________________________________________________________________
>> 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 users at lists.quantum-espresso.orghttps://lists.quantum-espresso.org/mailman/listinfo/users
>>
>> --
>> Dr. Lorenzo Paulatto
>> IR IMPMC - CNRS UMR 7590 / Sorbonne Université / MNHN
>> phone: +33 (0)1 442 79822 / telegram: lpaulatto
>> http://www.impmc.upmc.fr/~paulatto/ - https://anharmonic.github.io/
>> 23-24/423 B115, 4 place Jussieu 75252 Paris CX 05
>>
>> _______________________________________________________________________________
>> 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 users at lists.quantum-espresso.org
>> https://lists.quantum-espresso.org/mailman/listinfo/users
>
>
>
> --
>
> Iván Darío Arellano Ramírez
>
> Profesor Titular Programa de Ingeniería Física
>
> Director Grupo de Investigación en Modelado y Simulación Computacional
>
> Universidad Tecnológica de Pereira
>
> El contenido de este mensaje y sus anexos son únicamente para el uso del
> destinatario y pueden contener información clasificada o reservada. Si
> usted no es el destinatario intencional, absténgase de cualquier uso,
> difusión, distribución o copia de esta comunicación.
>
> _______________________________________________________________________________
> 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 users at lists.quantum-espresso.orghttps://lists.quantum-espresso.org/mailman/listinfo/users
>
> --
> Dr. Lorenzo Paulatto
> IR IMPMC - CNRS UMR 7590 / Sorbonne Université / MNHN
> phone: +33 (0)1 442 79822 / telegram: lpaulatto
> http://www.impmc.upmc.fr/~paulatto/ - https://anharmonic.github.io/
> 23-24/423 B115, 4 place Jussieu 75252 Paris CX 05
>
> _______________________________________________________________________________
> 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 users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
--
Iván Darío Arellano Ramírez
Profesor Titular Programa de Ingeniería Física
Director Grupo de Investigación en Modelado y Simulación Computacional
Universidad Tecnológica de Pereira
--
El contenido de este mensaje y sus anexos son únicamente para el uso del
destinatario y pueden contener información clasificada o reservada. Si
usted no es el destinatario intencional, absténgase de cualquier uso,
difusión, distribución o copia de esta comunicación.
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