<div dir="ltr"><div><div>Hello all,<br><br></div>I am trying to find the phonon frequencies of silicon under hydrostatic strain. The SCF file runs to completion, however when I run the ph.x code it give an error saying: <br>
</div>"Error in routine phq_readin (1):<br><div>The phonon code is not working after vc-relax"<br><br></div><div>Here's the scf input file<br>&control<br>    calculation='vc-relax'<br>    restart_mode='from_scratch',<br>
    outdir='../../../../OUTPUT/poster/strained',<br>    pseudo_dir='../../../../pseudo',<br>    prefix='hydro-silicon'<br>/<br>&system<br>    ibrav=2, celldm(1)=10.263, nat=2, ntyp=1,<br>    ecutwfc =20.0<br>
/<br>&electrons<br>    conv_thr =  1.0d-8<br>    mixing_beta = 0.7<br>/<br>&ions<br>    ion_dynamics='damp'<br>/<br>&cell<br>    cell_dynamics='damp-w',<br>    press=35.0,<br>    cell_dofree='all'<br>
/<br>ATOMIC_SPECIES<br> Si  28.0855 Si.pz-vbc.UPF<br>ATOMIC_POSITIONS<br> Si 0.00 0.00 0.00<br> Si 0.25 0.25 0.25<br>K_POINTS<br>   10<br>    0.1250000  0.1250000  0.1250000   1.00<br>    0.1250000  0.1250000  0.3750000   3.00<br>
    0.1250000  0.1250000  0.6250000   3.00<br>    0.1250000  0.1250000  0.8750000   3.00<br>    0.1250000  0.3750000  0.3750000   3.00<br>    0.1250000  0.3750000  0.6250000   6.00<br>    0.1250000  0.3750000  0.8750000   6.00<br>
    0.1250000  0.6250000  0.6250000   3.00<br>    0.3750000  0.3750000  0.3750000   1.00<br>    0.3750000  0.3750000  0.6250000   3.00<br>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br><br></div><div>here's the ph input file<br> &inputph<br>
   tr2_ph=1.0d-14,<br>   ldisp=.true.<br>   nq1=4, nq2=4, nq3=4,<br>   amass(1)= 28.0855,<br>   prefix='hydro-silicon'<br>   outdir='../../../../OUTPUT/poster/strained'<br>   fildyn='hydro-si.dyn'<br>
/<br>%%%%%%%%%%%%%%%%%%%5<br><br></div><div>and the output of ph.x (minus the general heading information)<br>     G-vector sticks info<br>     --------------------<br>     sticks:   dense  smooth     PW     G-vecs:    dense   smooth      PW<br>
     Sum         283     283     91                 3143     3143     561<br><br><br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>     Error in routine phq_readin (1):<br>     The phonon code is not working after vc-relax<br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>
<br>     stopping ...<br><br></div><div>Documentation in the ph.x user guide suggests that there's a problem with my scf run, however, I cannot seem to find the issue. Any help would be greatly appreciated.<br><br></div>
<div>Best,<br></div><div>Cameron Foss<br></div></div>