Hi Yuan, Your structure seems big, many nbnd. For such structure, smaller value of alpha_mix(1) in phonon input is helpful for convergence. Non inclusion of alpha_mix(1) in your input file implies that the default value of 0.7 would be used. Include alpha_mix(1) and use smaller value such as 0.2.
If that doesn't solve the problem, you may need to increase the convergence threshold tr2_ph. It is also helpful to split your job along the q-points. This will enable you monitor the convergence of different q-point and adjust parameters such as alpha_mix(1) and tr2_ph accordingly. Best, Isaiah On Mon, Oct 2, 2017 at 12:51 PM, yuan liang <[email protected]> wrote: > Dear QE developers and users, > > Recently I'm trying to calculate phonon dos via ph.x, however, although I > can get fine convergence result at gamma point, ph.x cannot reach > convergence within 100 steps and stop automaticly at the 1st non gamma > point on my mesh. > > The material is YVO3, orthorhombic, with 4 Y atom, 4 V atom and 12 O atom > per unit cell. > > The QE version is 5.4.0 > > I tried both GGA PBEsol USPP and LDA USPP(from THEOS SSSP) > > Are there any methods to solve this problem? Any suggestion will be welcome. > > Here are my input files: > *scf calculation* > &control > calculation= 'scf', > restart_mode= 'from_scratch', > prefix='YVO3_exc', > pseudo_dir = '...', > outdir= '...', > wf_collect=.true., > tprnfor=.true., tstress=.true. > / > &system > ibrav = 8, > celldm(1) = 9.9893, > celldm(2) = 1.0581, > celldm(3) = 1.4296, > nat = 20, > ntyp = 3, > ecutwfc = 60, > ecutrho = 480, > ecfixed = 60, > qcutz = 20, > q2sigma = 5, > occupations= 'smearing', smearing='gauss', degauss=0.01, > / > &electrons > mixing_beta = 0.4, > mixing_mode = 'plain', > conv_thr = 1.0d-10, > / > ATOMIC_SPECIES > Y 88.906 y_lda_v1.4.uspp.F.UPF > V 50.942 v_lda_v1.4.uspp.F.UPF > O 15.999 o_lda_v1.2.uspp.F.UPF > ATOMIC_POSITIONS crystal > Y 0.97830 0.07150 0.25000 > ... > O 0.18720 0.20040 0.55663 > K_POINTS automatic > 6 6 4 0 0 0 > *phonon calculation on grid* > &inputph > prefix='YVO3_exc', > outdir='...', > recover=.true., > *ldisp=.true*., > nq1=6, > nq2=6, > nq3=4, > tr2_ph=1.0d-14, > fildyn='YVO3_dyn.G', > amass(1)=80.906, > amass(2)=50.942, > amass(3)=15.999, > / > 0.000000 0.000000 0.000000 > > Best regards, > > Yuan Liang > Physics Department, > University of Virginia > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > -- Isaiah Abu Moses Graduate Student, Physics Department, University of Ibadan, Nigeria
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