<div class="gmail_quote"><br><br>Dear Pwscf users,<br>I have done the phonon calculation of Li2S using 4x4x4 (8-q-points) using this code. In this mail I am sending the scf file and the <a href="http://ph.in" target="_blank">ph.in</a> file and also the PDC obtained in <br>

0.0 0.0 0.0 to 1.0 0.0 0.0 <br>direction, (our results and the reported previous results JPCM 3 (1991) 1055-1064)<br><br>In our calculated PDC we are getting good agreement at gamma points. But when we draw in the whole brillouin zone we are getting an unwanted softening of optical and also one of the acoustic mode in the midway of G-X direction.<br>

Can anybody comment on this. <br>It will be really helpful for my PhD work.<br>Regards<br clear="all"><font color="#888888"> &CONTROL<br>               calculation = 'scf' ,<br>              restart_mode = 'from_scratch' ,<br>
                    outdir = './OUT',<br>             pseudo_dir = '/root/bipul/espresso-4.0.1/pseudo/Li2S',<br>             prefix = 'Li2S',<br>             etot_conv_thr = 1.0d-5 ,<br>             forc_conv_thr = 1.0d-4 ,<br>
                   tstress = .true. ,<br>                   tprnfor = .true. ,<br> /<br> &SYSTEM<br>                     ibrav = 2,<br>                 celldm(1) =  10.78750,<br>                       nat = 3,<br>                      ntyp = 2 ,<br>
                   ecutwfc = 32,<br>                   ecutrho = 600,<br>                  occupations = 'fixed' ,<br>                  smearing = 'methfessel-paxton',<br> !                  degauss = 0.01<br>
 /<br> &ELECTRONS<br>               mixing_beta = 0.5 ,<br>            conv_thr =  1.0d-8<br>           diagonalization = 'david' ,<br> /<br> &IONS<br> /<br>ATOMIC_SPECIES<br> S   32.066  S.pw91-van_ak.UPF<br>
 Li  6.914   Li.pw91-s-van_ak.UPF<br>ATOMIC_POSITIONS (crystal)<br>S  0.0 0.0 0.0<br>Li 0.25 0.25 0.25<br>Li 0.75 0.75 0.75<br>K_POINTS automatic<br>   8  8  8 1 1 1<br><br><br><br></font></div>phonons of Li2S<br> &inputph<br>
  recover =.true.,<br>  tr2_ph=1.0d-14,<br>  alpha_mix(1)=0.4,<br>  prefix='Li2S',<br>  amass(1)=32.066,<br>  amass(2)=6.941,<br>  outdir='./OUT',<br>  fildyn='li2s.dyn',<br>  epsil= .true.,<br>  trans= .true.,<br>
! ldisp=.true.<br> nq1=4, nq2=4, nq3=4<br> /<br>~                                                                                                                            <br>~     <br><br clear="all"><br>-- <br>Premlata Pandit<br>
Ph.d. student,<br>Barkatullah university,<br>Bhopal 462026,<br>MP, India <br>