Hi Iyad, How strong is the failure to converge at (0, 1/6, 1/6)? Perhaps a less tight tr2_ph value of, say, 1.0d-10 would get you where you need to be.
--William On Aug 10, 2012, at 12:29 PM, Iyad AL-QASIR wrote: > Dear PW_Forum, > > I am running phonon calculations for FeSi (a narrow band gap semiconductor) > using QE-5.0. I am using a 6x6x6 q-vectors mesh. The first 4 q-points ran > successfully and got good phonon values. However when I reach the 5th point(0 > 1/6 1/6). The self-consistent calculations do not converge. I tried to reduce > alpha_mix(1) to 0.3 but still have the same problem. > > Below are my input files: > > &control > calculation='scf', > restart_mode='from_scratch', > title='FeSi', > outdir='./', > prefix='FeSi', > pseudo_dir='./', > / > &system > ibrav=1, > celldm(1)=8.4165, > nat=8, ntyp=2, > ecutwfc=60.0, > ecutrho= 720.0, > / > &electrons > conv_thr=1.0d-9, > mixing_mode='plain', > mixing_beta=0.7, > diagonalization='david', > / > ATOMIC_SPECIES > Fe 55.847 Fe.pw91-sp-van_ak.UPF > Si 28.086 Si.pw91-n_van.UPF > ATOMIC_POSITIONS > Fe 0.134855265 0.134855265 0.134855265 > Fe 0.634855265 0.365144735 0.865144735 > Fe 0.865144735 0.634855265 0.365144735 > Fe 0.365144735 0.865144735 0.634855265 > Si 0.839976366 0.839976366 0.839976366 > Si 0.339976366 0.660023634 0.160023634 > Si 0.160023634 0.339976366 0.660023634 > Si 0.660023634 0.160023634 0.339976366 > K_POINTS {automatic} > 10 10 10 0 0 0 > *********************************** > phonons of FeSi > &inputph > tr2_ph=1.0d-14, > prefix='FeSi', > amass(1)=55.847, > amass(2)=28.086, > outdir='./' > fildyn='FeSi.dyn', > trans=.true., > ldisp=.true., > nq1=6, nq2=6, nq3=6 > recover=.true., > alpha_mix(1)=0.30 > > Any comments and suggestions are welcomed. > > Thanks > IYAD > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum ********************************************************* William D. Parker phone: (630) 252-4834 Computational Postdoctoral Fellow fax: (630) 252-4798 MSD-212, Rm. C-215 Argonne National Laboratory 9700 S. Cass Ave. Argonne, IL 60439 *********************************************************