<div>Thanks for the heads-up! The system is a molecular crystal. I monitored the memory usage, which was fine.</div>
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<div>My input file is like the following:</div>
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<div>&control<br>    calculation='relax'<br>    restart_mode='from_scratch',<br>    wf_collect=.true.,<br>    prefix='pwscf',<br>    pseudo_dir = '/home/winey/pseudo',<br>    outdir='.', 
<br>    forc_conv_thr = 0.001<br>   tprnfor=.true.<br> /<br> &system<br>      ibrav = 8<br>      celldm(1) = 16.223<br>      celldm(2) = 3.2124</div>
<div>      celldm(3) = 1.1942<br>    nat=248, ntyp=2,<br>    ecutwfc = 30.0,<br>    occupations='fixed',     <br> /<br> &electrons<br>    conv_thr =  1.0d-8<br>    mixing_beta = 0.3<br> /  <br> &ions <br>
   upscale=10<br> /<br>ATOMIC_SPECIES<br>C   12.0107 C.pbe-van_ak.UPF<br>H   1.00794 H.pbe-van_ak.UPF<br>K_POINTS {gamma}<br>ATOMIC_POSITIONS {crystal}<br>C ....</div>
<div>...</div>
<div>H ...</div>
<div>... </div>