<div dir="ltr"><pre style="color:rgb(0,0,0)">Dear QE users,</pre><pre style="color:rgb(0,0,0)">I am a beginner in QE and am performing some calculation on phonons of YVO3 in order to get the phonon dos</pre><pre style="color:rgb(0,0,0)">I ran SCF first and then did PH.x at a grid of 3*3*2 with 8 irreducible q-vectors. </pre><pre style="color:rgb(0,0,0)">However in ph.x output file of this specific q-point(0.0, 0.315030085373153, -0.349748181309457E), </pre><pre style="color:rgb(0,0,0)">I got this error message on mode #12:</pre><pre><font color="#000000"><i>Representation # 12 mode # 12
Self-consistent Calculation
kpoint 1 ibnd 87 solve_linter: root not converged NaN
kpoint 2 ibnd 88 solve_linter: root not converged NaN
kpoint 3 ibnd 89 solve_linter: root not converged NaN
kpoint 4 ibnd 87 solve_linter: root not converged NaN
kpoint 5 ibnd 88 solve_linter: root not converged NaN
kpoint 6 ibnd 89 solve_linter: root not converged NaN
kpoint 7 ibnd 89 solve_linter: root not converged NaN
kpoint 8 ibnd 89 solve_linter: root not converged NaN
kpoint 9 ibnd 89 solve_linter: root not converged NaN
kpoint 10 ibnd 89 solve_linter: root not converged NaN
kpoint 11 ibnd 91 solve_linter: root not converged NaN
kpoint 12 ibnd 93 solve_linter: root not converged NaN
kpoint 13 ibnd 87 solve_linter: root not converged NaN
kpoint 14 ibnd 88 solve_linter: root not converged NaN
kpoint 15 ibnd 87 solve_linter: root not converged NaN
kpoint 16 ibnd 88 solve_linter: root not converged NaN
kpoint 17 ibnd 88 solve_linter: root not converged NaN
kpoint 18 ibnd 89 solve_linter: root not converged NaN
kpoint 19 ibnd 88 solve_linter: root not converged NaN
kpoint 20 ibnd 88 solve_linter: root not converged NaN
kpoint 21 ibnd 89 solve_linter: root not converged NaN
kpoint 22 ibnd 89 solve_linter: root not converged NaN
kpoint 23 ibnd 89 solve_linter: root not converged NaN
kpoint 24 ibnd 89 solve_linter: root not converged NaN
kpoint 25 ibnd 88 solve_linter: root not converged NaN
kpoint 26 ibnd 88 solve_linter: root not converged NaN
kpoint 27 ibnd 89 solve_linter: root not converged NaN
kpoint 28 ibnd 89 solve_linter: root not converged NaN
kpoint 29 ibnd 89 solve_linter: root not converged NaN
kpoint 30 ibnd 89 solve_linter: root not converged NaN
kpoint 31 ibnd 89 solve_linter: root not converged NaN
kpoint 32 ibnd 89 solve_linter: root not converged NaN
kpoint 33 ibnd 89 solve_linter: root not converged NaN
kpoint 34 ibnd 89 solve_linter: root not converged NaN
kpoint 35 ibnd 89 solve_linter: root not converged NaN
kpoint 36 ibnd 89 solve_linter: root not converged NaN
kpoint 37 ibnd 89 solve_linter: root not converged NaN
kpoint 38 ibnd 89 solve_linter: root not converged NaN
kpoint 39 ibnd 93 solve_linter: root not converged NaN
kpoint 40 ibnd 91 solve_linter: root not converged NaN
kpoint 41 ibnd 89 solve_linter: root not converged NaN
kpoint 42 ibnd 91 solve_linter: root not converged NaN
kpoint 43 ibnd 89 solve_linter: root not converged NaN
kpoint 44 ibnd 89 solve_linter: root not converged NaN
kpoint 45 ibnd 89 solve_linter: root not converged NaN
kpoint 46 ibnd 89 solve_linter: root not converged NaN
kpoint 47 ibnd 89 solve_linter: root not converged NaN
kpoint 48 ibnd 89 solve_linter: root not converged NaN
kpoint 49 ibnd 87 solve_linter: root not converged NaN
kpoint 50 ibnd 88 solve_linter: root not converged NaN
kpoint 51 ibnd 89 solve_linter: root not converged NaN
kpoint 52 ibnd 89 solve_linter: root not converged NaN
kpoint 53 ibnd 89 solve_linter: root not converged NaN
kpoint 54 ibnd 89 solve_linter: root not converged NaN
kpoint 55 ibnd 88 solve_linter: root not converged NaN
kpoint 56 ibnd 88 solve_linter: root not converged NaN
kpoint 57 ibnd 89 solve_linter: root not converged NaN
kpoint 58 ibnd 88 solve_linter: root not converged NaN
kpoint 59 ibnd 88 solve_linter: root not converged NaN
kpoint 60 ibnd 89 solve_linter: root not converged NaN
kpoint 61 ibnd 89 solve_linter: root not converged NaN
kpoint 62 ibnd 89 solve_linter: root not converged NaN
kpoint 63 ibnd 89 solve_linter: root not converged NaN
kpoint 64 ibnd 89 solve_linter: root not converged NaN
kpoint 65 ibnd 89 solve_linter: root not converged NaN
kpoint 66 ibnd 89 solve_linter: root not converged NaN
kpoint 67 ibnd 91 solve_linter: root not converged NaN
kpoint 68 ibnd 89 solve_linter: root not converged NaN
kpoint 69 ibnd 91 solve_linter: root not converged NaN
kpoint 70 ibnd 89 solve_linter: root not converged NaN
kpoint 71 ibnd 89 solve_linter: root not converged NaN
kpoint 72 ibnd 89 solve_linter: root not converged NaN</i></font><span style="color:rgb(0,0,0)">
</span></pre><div>...(it goes on till the very end with a "<i>Error in routine broyden (1):factorization</i>" error message)</div><div>I have searched the mail list and do find some similar problems, but I couldn't find a working solution for now. Some would suggest that I tweak the nmix_ph(increase or decrease?), alpha_mix(lower to 0.1) and tr2_ph(increase), but since the other 7 q-vectors converged well(although some of them converge very slow) and I need to combine all the data in outdir/_phprefix.phsave into one directory for the final dynamical matrix, I'm not sure if I need to redo all the other 7 q-vectors and keep the three parameters(nmix_ph, alpha_mix, tr2_ph) consistent if I were to change them for this q-vector. </div><div><br></div><div>I attached my input script for both scf and phonon calculation below,.</div><div><b>1)pw.x input:</b></div><div><div>&control</div><div> calculation= 'scf',</div><div> restart_mode= 'from_scratch',</div><div> prefix='YVO3_exc',</div><div> pseudo_dir = '...',</div><div> outdir= '...',</div><div> wf_collect=.true.,</div><div> tprnfor=.true., tstress=.true.</div><div>/</div><div>&system</div><div> ibrav = 8,</div><div> celldm(1) = 9.9893, </div><div> celldm(2) = 1.0581, </div><div> celldm(3) = 1.4296,</div><div> nat = 20,</div><div> ntyp = 3,</div><div> ecutwfc = 100,</div><div> ecfixed = 60,</div><div> qcutz = 20,</div><div> q2sigma = 5,</div><div> occupations= 'smearing', smearing='gauss', degauss=0.01,</div><div>/</div><div>&electrons</div><div> mixing_beta = 0.1,</div><div> mixing_mode = 'plain',</div><div> conv_thr = 1.0d-10,</div><div>/ </div><div>&ions</div><div>/</div><div>&cell</div><div>/</div><div>ATOMIC_SPECIES</div><div> Y 88.906 y_lda_v1.4.uspp.F.UPF</div><div> V 50.942 v_lda_v1.4.uspp.F.UPF</div><div> O 15.999 o_lda_v1.2.uspp.F.UPF</div><div>ATOMIC_POSITIONS crystal</div><div>Y 0.976995537 0.075721635 0.250000000</div><div>Y 0.023004463 0.924278365 0.750000000</div><div>Y 0.476995737 0.424277671 0.750000000</div><div>Y 0.523004263 0.575722329 0.250000000</div><div>V 0.500000000 1.000000000 -0.000000000</div><div>V 0.000000000 0.500000000 1.000000000</div><div>V 0.500000000 1.000000000 0.500000000</div><div>V -0.000000000 0.500000000 0.500000000</div><div>O 0.106387022 0.466777211 0.250000000</div><div>O 0.893612978 0.533222789 0.750000000</div><div>O 0.606387124 0.033223066 0.750000000</div><div>O 0.393612876 0.966776934 0.250000000</div><div>O 0.691854045 0.297781009 0.050393568</div><div>O 0.308145955 0.702218991 0.949606432</div><div>O 0.191854168 0.202219259 0.949606353</div><div>O 0.808145832 0.797780741 0.050393647</div><div>O 0.308145955 0.702218991 0.550393568</div><div>O 0.691854045 0.297781009 0.449606432</div><div>O 0.808145832 0.797780741 0.449606353</div><div>O 0.191854168 0.202219259 0.550393647</div><div>K_POINTS automatic</div><div> 6 6 4 0 0 0</div></div><div><br></div><div><b>2)ph.x input</b></div><div><div>Phonons on a grid</div><div>&inputph</div><div> prefix='YVO3_exc',</div><div> outdir='...',</div><div> recover=.true.,</div><div> ldisp=.true.,</div><div> nq1=3,</div><div> nq2=3,</div><div> nq3=2,</div><div> tr2_ph=1.0d-14,</div><div> alpha_mix(1)=0.2,</div><div> fildyn='YVO3_dyn.G',</div><div> start_q=#,</div><div> last_q=#,</div><div> amass(1)=80.906,</div><div> amass(2)=50.942,</div><div> amass(3)=15.999,</div><div>/</div><div style="font-weight:bold"><br></div></div><div style="">Thank you so much for any suggestion and help,</div><div style="">Best regards,</div><div style=""><br></div><div style="">Yuan Liang</div><div style="">Physics Department</div><div style="">University of Virginia</div></div>