Dear PW_Forum,<br><br>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.<br>
<br>Below are my input files:<br><br>&control<br> calculation='scf',<br> restart_mode='from_scratch',<br> title='FeSi',<br> outdir='./',<br> prefix='FeSi',<br> pseudo_dir='./',<br>
/<br>&system<br> ibrav=1,<br> celldm(1)=8.4165,<br> nat=8, ntyp=2,<br> ecutwfc=60.0,<br> ecutrho= 720.0,<br>/<br>&electrons<br> conv_thr=1.0d-9,<br> mixing_mode='plain',<br> mixing_beta=0.7,<br> diagonalization='david',<br>
/<br>ATOMIC_SPECIES<br>Fe 55.847 Fe.pw91-sp-van_ak.UPF<br>Si 28.086 Si.pw91-n_van.UPF<br>ATOMIC_POSITIONS<br>Fe 0.134855265 0.134855265 0.134855265<br>Fe 0.634855265 0.365144735 0.865144735<br>Fe 0.865144735 0.634855265 0.365144735<br>
Fe 0.365144735 0.865144735 0.634855265<br>Si 0.839976366 0.839976366 0.839976366<br>Si 0.339976366 0.660023634 0.160023634<br>Si 0.160023634 0.339976366 0.660023634<br>Si 0.660023634 0.160023634 0.339976366<br>
K_POINTS {automatic}<br>10 10 10 0 0 0<br>***********************************<br>phonons of FeSi<br> &inputph<br> tr2_ph=1.0d-14,<br> prefix='FeSi',<br> amass(1)=55.847,<br> amass(2)=28.086,<br> outdir='./'<br>
fildyn='FeSi.dyn',<br> trans=.true.,<br> ldisp=.true.,<br> nq1=6, nq2=6, nq3=6<br> recover=.true.,<br> alpha_mix(1)=0.30<br><br>Any comments and suggestions are welcomed.<br><br>Thanks<br>IYAD<br clear="all">
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