<div dir="ltr"><div><div><div>dear users<br></div>I want to calculate phonon properties of cinnabar hexagonal structure of HgTe, but when I reun ph.x some of the frequencies are negative. why this happen? could anyone help me in this?<br>
</div>Shahid Chamran University of Ahwaz<br><br>the scf file:<br>&CONTROL<br> calculation='scf'<br> restart_mode='from_scratch',<br> outdir='/home/1/tmp/',<br> prefix='ph',<br>
pseudo_dir = '/home/1/pseudo/',<br> tstress = .TRUE.,<br> tprnfor = .TRUE., <br> verbosity = 'high',<br> /<br> &SYSTEM<br> ibrav = 4, <br> celldm(1) = 8.410,<br> celldm(3) = 2.276,<br>
nat = 6<br> ntyp = 2,<br> nspin = 1,<br> ecutwfc = 40,<br> ecutrho = 160,<br> occupations = 'smearing',<br> degauss = 0.01,<br> smearing ='mp',<br>
/<br> &ELECTRONS<br>
conv_thr=1.D-7,<br> mixing_beta=0.7,<br>/<br> &IONS<br> /<br>ATOMIC_SPECIES <br> Hg 200.59 80-Hg.GGA.fhi.UPF<br> Te 127.6 52-Te.GGA.fhi.UPF<br>ATOMIC_POSITIONS (crystal)<br>Hg 0.641 0.000 0.333<br>
Hg 0.000 0.641 0.666<br>Hg 0.359 0.359 0.000<br>Te 0.562 0.000 0.833<br>Te 0.000 0.562 0.166<br>Te 0.438 0.438 0.500 <br>K_POINTS crystal <br>36 <br> 0.000000000 0.000000000 0.000000000 1.000000000 <br>
0.066000000 0.066000000 0.000000000 1.000000000 <br> 0.132000000 0.132000000 0.000000000 1.000000000 <br> 0.198000000 0.198000000 0.000000000 1.000000000 <br> 0.264000000 0.264000000 0.000000000 1.000000000 <br>
0.330000000 0.330000000 0.000000000 1.000000000 <br> 0.364000000 0.264000000 0.000000000 1.000000000 <br> 0.398000000 0.198000000 0.000000000 1.000000000 <br> 0.432000000 0.132000000 0.000000000 1.000000000 <br>
0.466000000 0.066000000 0.000000000 1.000000000 <br> 0.500000000 0.000000000 0.000000000 1.000000000 <br> 0.400000000 0.000000000 0.000000000 1.000000000 <br> 0.300000000 0.000000000 0.000000000 1.000000000 <br>
0.200000000 0.000000000 0.000000000 1.000000000 <br> 0.100000000 0.000000000 0.000000000 1.000000000 <br> 0.000000000 0.000000000 0.000000000 1.000000000 <br> 0.000000000 0.000000000 0.100000000 1.000000000 <br>
0.000000000 0.000000000 0.200000000 1.000000000 <br> 0.000000000 0.000000000 0.300000000 1.000000000 <br> 0.000000000 0.000000000 0.400000000 1.000000000 <br> 0.000000000 0.000000000 0.500000000 1.000000000 <br>
0.000000000 0.100000000 0.500000000 1.000000000 <br> 0.000000000 0.200000000 0.500000000 1.000000000 <br> 0.000000000 0.300000000 0.500000000 1.000000000 <br> 0.000000000 0.400000000 0.500000000 1.000000000 <br>
0.000000000 0.500000000 0.500000000 1.000000000 <br> 0.066000000 0.466000000 0.500000000 1.000000000 <br> 0.132000000 0.432000000 0.500000000 1.000000000 <br> 0.198000000 0.398000000 0.500000000 1.000000000 <br>
0.264000000 0.364000000 0.500000000 1.000000000 <br> 0.330000000 0.330000000 0.500000000 1.000000000 <br> 0.264000000 0.264000000 0.500000000 1.000000000 <br> 0.198000000 0.198000000 0.500000000 1.000000000 <br>
0.132000000 0.132000000 0.500000000 1.000000000 <br> 0.066000000 0.066000000 0.500000000 1.000000000 <br> 0.000000000 0.000000000 0.500000000 1.000000000 <br> 0.000000000 0.000000000 0.400000000 1.000000000 <br>
0.000000000 0.000000000 0.300000000 1.000000000 <br> 0.000000000 0.000000000 0.200000000 1.000000000 <br> 0.000000000 0.000000000 0.100000000 1.000000000 <br> 0.000000000 0.000000000 0.000000000 1.000000000 <br>
<br></div>the ph file:<br>phonons of HgTe<br> &inputph<br> tr2_ph=1.0d-12,<br> ldisp=.true.,<br> nq1=3, nq2=3 ,nq3=2<br> amass(1)=200.59,<br> amass(2)=127.6,<br> outdir='/home/1/tmp/',<br> prefix='ph',<br>
fildyn='cinn.dyn',<br> /<br><div><br></div></div>