<div dir="auto"><div style="font-family:sans-serif;font-size:12.8px" dir="auto"><div style="margin:16px 0px"><div><div dir="ltr"><div><div><div><br>Dear All,<br><br></div>I am trying to reproduce published data but wihtout Vdw i got wrong results and then after including DFT-D3 , my calculations are not converging for vc-relax.Please see my i/p  file. I have just started using QE so i am not sure whats wrong however i have read threads containing similar problems. I tried reducing beta to 0.2 and change nbnd and diagonalization but to no avail . I have also used the suggested ecutwfc=40 in the paper  but my calculations didnt converge even after 500 iterations. Please help me.<br>&CONTROL<br> calculation='vc-relax',<br> restart_mode='from_scratch',<br> prefix='Cs',<br> pseudo_dir="/home/external/iitb/priyas/PSEUDOPOTENTIALS_PBE",<br> tstress = .true.<br> tprnfor = .true.<br> verbosity= 'high',<br> forc_conv_thr=1.0d-3,<br> etot_conv_thr=1.0d-5,<br>/<br>&SYSTEM<br> a           = 10.6212,<br> ibrav       = 2,<br> nat         = 3,<br> ntyp        = 3,<br> ecutwfc= 20.0,<br> ecutrho=400.0,<br> vdw_corr='DFT-D3',<br> nbnd=35,<br> occupations='smearing',<br> degauss=0.001, <br>/<br>&ELECTRONS<br> mixing_beta=0.2,<br> diagonalization='cg',<br> conv_thr=1d-8,<br> electron_maxstep=500,<br>/<br>&IONS<br> ion_dynamics='bfgs',<br>/<br>&CELL<br> cell_dynamics='bfgs'<br> press=0.0,<br> press_conv_thr=0.5,<br>/<br>ATOMIC_SPECIES<br>Cs 132.905 Cs.pbe-spn-kjpaw_psl.1.0.0.UPF<br>Ti 47.867  Tl.pbe-dn-kjpaw_psl.1.0.0.UPF<br>Br 79.904  Br.pbe-n-kjpaw_psl.1.0.0.UPF<br>ATOMIC_POSITIONS crystal<br>Cs      0.250000   0.250000   0.250000<br>Ti      0.000000   0.000000   0.000000<br>Br      0.234000   0.000000   0.000000<br>K_POINTS automatic<br>4 4 4 1 1 1<br>,<br></div>Regards,<br></div>Priya,IITB<br></div></div></div><div style="height:0px"></div></div><br></div>