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    <p>Hhelo,</p>
    <p>increase nmix_ph and reduce alpha_mix, in a difficult case
      recently I have used:</p>
    <p>  <span style="font-family:monospace"><span
          style="color:#000000;background-color:#ffffff;">nmix_ph=10</span><span
          style="color:#000000;background-color:#ffffff;">
        </span><br>
        <span style="color:#000000;background-color:#ffffff;">
           alpha_mix=.25</span><br>
        <span style="color:#000000;background-color:#ffffff;">
        </span><br>
      </span>
    </p>
    <div class="moz-cite-prefix">Also, the convergence of the scf
      process in pw.x should be tighter, something like</div>
    <div class="moz-cite-prefix">    conv_thr =  1.0d-12</div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">Because the total energy is
      variational, but the phonons are not, they converge much slower
      with this threshold.<br>
    </div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">hth</div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">On 06/06/2025 21:48, Ivan Dario
      Arellano Ramirez wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAEHQCDNDMpy8UFZbK-7PAwEkwy9HfhFKS2Ry0Pz8dvTsX60rwA@mail.gmail.com">
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        <div>I QE users</div>
        <div><br>
        </div>
        <div>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.</div>
        <div><br>
        </div>
        <div>Pert. #  1: Fermi energy shift (Ry) =    -5.5393E+02    
          0.0000E+00<br>
          <br>
                iter # 150 total cpu time : 13815.8 secs   <a
            href="http://av.it" moz-do-not-send="true">av.it</a>.:   5.3<br>
                thresh= 4.679E-04 alpha_mix =  0.700 |ddv_scf|^2 =
           4.318E-06<br>
          <br>
               End of self-consistent calculation<br>
          <br>
               No convergence has been achieved</div>
        <div><br>
        </div>
        <div><br>
        </div>
        <div>This is an overview of the two approaches I followed:</div>
        <div><br>
          1) perform very dense scf calculation with la2F=.true. in
          &systems (Likely, I am exceeding the maximum of 40000 k
          points)</div>
        <div>2) normal scf on coarser k-mesh</div>
        <div>3) phonon calculation using ph.x</div>
        <div>4) Inverse Fourier transform of dynamical matrix and the
          phonon linewidth using q2r.x</div>
        <div>5) Fourier transform to obtain dynamical matrix and the
          phonon linewidth using matdyn.x</div>
        <div><br>
        </div>
        <div>The other tutorial proposed an initial scf calculation
          followed by an nscf calculation with la2F=.true. the rest of
          steps are the same.</div>
        <div><br>
        </div>
        <div>Here are all the inputs.</div>
        <div><br>
        </div>
        <div>Any suggestions or insights would be greatly appreciated.</div>
        <div><br>
        </div>
        <div><br>
        </div>
        <div>1) very dense k-mesh scf</div>
        <div><br>
        </div>
        <div>&control<br>
              calculation = 'scf'<br>
              restart_mode='from_scratch',<br>
              prefix='inn_ep',<br>
              tstress = .true.<br>
              tprnfor = .true.<br>
              pseudo_dir = '/home/pps/pbe.0.3.1/PSEUDOPOTENTIALS/',<br>
              outdir='./tmp'<br>
              verbosity = 'high'<br>
              etot_conv_thr = 1.d-6<br>
              forc_conv_thr = 1.d-5<br>
          /<br>
          &system<br>
              ibrav = 0, <br>
              nat=  4,<br>
              ntyp= 2,<br>
              ecutwfc = 90,<br>
              ecutrho = 900,<br>
              occupations='smearing',<br>
              smearing='m-v',<br>
              degauss=0.02,<br>
              la2F = .true.<br>
          /<br>
          &electrons<br>
              conv_thr =  1.0d-8<br>
              electron_maxstep = 200,<br>
              mixing_mode = 'plain'<br>
              mixing_beta = 0.3D0<br>
              diagonalization  = 'david'      <br>
           /<br>
          ATOMIC_SPECIES<br>
          In   114.818    In.pbe-dn-rrkjus_psl.1.0.0.UPF<br>
          N   14.007      N.pbe-n-rrkjus_psl.1.0.0.UPF<br>
          CELL_PARAMETERS angstrom<br>
             1.793358573  -3.106188164   0.000000000<br>
             1.793358573   3.106188164   0.000000000<br>
             0.000000000   0.000000000   5.799337066<br>
          <br>
          ATOMIC_POSITIONS crystal<br>
          In            0.3333330000        0.6666670000      
          -0.0019331848<br>
          In            0.6666670000        0.3333330000      
           0.4980668152<br>
          N             0.3333330000        0.6666670000      
           0.3767331848<br>
          N             0.6666670000        0.3333330000      
           0.8767331848 <br>
          K_POINTS automatic<br>
          45 45 36 0 0 0<br>
          <br>
        </div>
        <div>2) normal scf</div>
        <div><br>
        </div>
        <div>&control<br>
              calculation = 'scf'<br>
              restart_mode='from_scratch',<br>
              prefix='inn_ep',<br>
              tstress = .true.<br>
              tprnfor = .true.<br>
              pseudo_dir = '/home/pps/pbe.0.3.1/PSEUDOPOTENTIALS/',<br>
              outdir='./tmp'<br>
              verbosity = 'high'<br>
              etot_conv_thr = 1.d-6<br>
              forc_conv_thr = 1.d-5<br>
          /<br>
          &system<br>
              ibrav = 0, <br>
              nat=  4,<br>
              ntyp= 2,<br>
              ecutwfc = 90,<br>
              ecutrho = 900,<br>
              occupations='smearing',<br>
              smearing='m-v',<br>
              degauss=0.02,<br>
          /<br>
          &electrons<br>
              conv_thr =  1.0d-8<br>
              electron_maxstep = 200,<br>
              mixing_mode = 'plain'<br>
              mixing_beta = 0.3D0<br>
              diagonalization  = 'david'      <br>
           /<br>
          ATOMIC_SPECIES<br>
          In   114.818    In.pbe-dn-rrkjus_psl.1.0.0.UPF<br>
          N   14.007      N.pbe-n-rrkjus_psl.1.0.0.UPF<br>
          CELL_PARAMETERS angstrom<br>
             1.793358573  -3.106188164   0.000000000<br>
             1.793358573   3.106188164   0.000000000<br>
             0.000000000   0.000000000   5.799337066<br>
          <br>
          ATOMIC_POSITIONS crystal<br>
          In            0.3333330000        0.6666670000      
          -0.0019331848<br>
          In            0.6666670000        0.3333330000      
           0.4980668152<br>
          N             0.3333330000        0.6666670000      
           0.3767331848<br>
          N             0.6666670000        0.3333330000      
           0.8767331848 <br>
          K_POINTS automatic<br>
          15 15 12 0 0 0<br>
          <br>
        </div>
        <div>3) phonon calculation</div>
        <div><br>
        </div>
        <div>Phonons of InN at G!=0<br>
          &inputph<br>
           tr2_ph = 1.0d-14,<br>
           ldisp = .true.,<br>
           prefix = 'inn_ep',<br>
           recover = .true.<br>
           fildyn = 'inn-ph.dyn',<br>
           fildvscf = 'inndv'<br>
           nq1 = 5,<br>
           nq2 = 5,<br>
           nq3 = 3,<br>
           electron_phonon = 'interpolated'<br>
           el_ph_nsigma = 10<br>
           el_ph_sigma = 0.02<br>
           amass(1) = 114.818,<br>
           amass(2) = 14.007,<br>
           outdir =  './tmp'<br>
           /<br>
          <br>
           4) Inverse Fourier Transform<br>
        </div>
        <div><br>
        </div>
        <div>&INPUT<br>
           fildyn = 'inn-ph.dyn',<br>
           zasr = 'crystal',<br>
           flfrc =  'inn-ph.fc',<br>
           la2F = .true.<br>
           /<br>
        </div>
        <div><br>
        </div>
        <div>5) Fourier Transform</div>
        <div><br>
        </div>
        <div>&input<br>
           asr = 'crystal',<br>
           flfrc = 'inn-ph.fc',<br>
           flfrq = 'inn.band.freq'<br>
           flvec = 'inn.band.modes'<br>
           amass(1) = 114.818,<br>
           amass(2) = 14.007,<br>
           q_in_band_form = .true.<br>
           la2F = .true.<br>
           /<br>
          8<br>
             0.0000000000     0.0000000000     0.0000000000  40  ! Gamma<br>
             0.5000000000     0.0000000000     0.0000000000  25  ! M<br>
             0.3333333333     0.3333333333     0.0000000000  40  ! K<br>
             0.0000000000     0.0000000000     0.0000000000  25  ! Gamma<br>
             0.0000000000     0.0000000000     0.5000000000  40  ! A<br>
             0.5000000000     0.0000000000     0.5000000000  25  ! L<br>
             0.3333333333     0.3333333333     0.5000000000  40  ! H<br>
             0.0000000000     0.0000000000     0.5000000000  1   ! A</div>
        <div><br>
        </div>
        <div><br>
        </div>
        <div>Best regards,</div>
        <div><br>
        </div>
        <span class="gmail_signature_prefix">-- </span><br>
        <div dir="ltr" class="gmail_signature"
          data-smartmail="gmail_signature">
          <div dir="ltr">
            <div dir="ltr">
              <div>
                <div>
                  <p class="MsoNormal"
style="background-image:initial;background-position:initial;background-repeat:initial"><span
                      style="font-family:Arial,sans-serif">Iván Darío
                      Arellano Ramírez</span></p>
                  <p class="MsoNormal"
style="background-image:initial;background-position:initial;background-repeat:initial"><span
                      style="font-family:Arial,sans-serif">Profesor
                      Titular Programa de Ingeniería Física</span></p>
                  <p class="MsoNormal"
style="background-image:initial;background-position:initial;background-repeat:initial"><span
                      style="font-family:Arial,sans-serif">Director
                      Grupo de Investigación en Modelado y Simulación
                      Computacional</span></p>
                  <p class="MsoNormal" style="text-align:justify"><span
style="font-family:Arial,sans-serif;background-image:initial;background-position:initial;background-repeat:initial">Universidad
                      Tecnológica de Pereira</span><span lang="RU"></span></p>
                </div>
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      <br>
      <span
style="font-family:arial,sans-serif;font-size:12.8px;text-align:justify;background-color:rgb(255,255,255)">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.</span>
      <br>
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    <div class="moz-signature">-- <br>
      <small>Dr. Lorenzo Paulatto<br>
        IR IMPMC - CNRS UMR 7590 / Sorbonne Université / MNHN <br>
        phone: +33 (0)1 442 79822 / telegram: lpaulatto<br>
        <a href="http://www.impmc.upmc.fr/~paulatto/"
          class="moz-txt-link-freetext">http://www.impmc.upmc.fr/~paulatto/</a>
        - <a href="https://anharmonic.github.io/"
          class="moz-txt-link-freetext">https://anharmonic.github.io/</a><br>
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