Dear all,<br> I am trying to do phonon calculation of bcc-Zr from (0,0,0) to (1,1,1) in q-space.But I am getting negative frequencies in several q-points, also my curve is very different from experimental one. I optimized the system w.r.t ecutwf, ecutrho ,conv_thr, k-point sampling .I also tried the same calculation by changing potential also.I am new fellow in this field so I am unable to understand what is happening wrong !!<br>
My input files are :<br>1) <a href="http://zr.scf.in">zr.scf.in</a><br> &control<br> calculation='scf'<br> restart_mode='from_scratch',<br> tstress = .true.<br> tprnfor = .true.<br> prefix='zr',<br>
pseudo_dir = '/home/general/Desktop/espresso-4.0.5/pseudo/',<br> outdir='./'<br> /<br> &system<br> ibrav= 0, celldm(1) =6.7, nat= 1, ntyp= 1,<br> degauss=0.04,<br> smearing='mp',<br>
occupations='smearing',<br> ecutwfc =35.0<br> ecutrho = 350.0<br> /<br> &electrons<br> conv_thr = 1.0d-8<br> mixing_beta = 0.7<br> /<br>ATOMIC_SPECIES<br> Zr 91.22 Zr.pbe-nsp-van.UPF<br>ATOMIC_POSITIONS<br>
Zr 0.00 0.00 0.00<br>K_POINTS AUTOMATIC<br> 16 16 16 0 0 0 <br>CELL_PARAMETERS { cubic }<br> -0.500000000000000 0.500000000000000 0.500000000000000<br> 0.500000000000000 -0.500000000000000 0.500000000000000<br>
0.500000000000000 0.500000000000000 -0.500000000000000<br> ##########################################<br>2) <a href="http://zr.ph.in">zr.ph.in</a><br>phonons of Zr<br> &inputph<br> tr2_ph=1.0d-10,<br> prefix='zr',<br>
ldisp=.true.,<br> nq1=8, nq2=8, nq3=8<br> amass(1)=91.22,<br> outdir='./',<br> fildyn='zr.dyn',<br> /<br>Any one can help me please . <br>Thanks in advance.<br>P S Ghosh<br>B.A.R.C.<br>India<br>