Dear All,<br>&nbsp;&nbsp;&nbsp;&nbsp; I have a question about this input file in example03.<br>cat &gt; <a href="http://al001.mm.in">al001.mm.in</a> &lt;&lt; EOF<br>&amp;CONTROL<br>&nbsp; calculation = &quot;relax&quot;,<br>&nbsp;<b> dt&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 30.D0,</b><br>
&nbsp; pseudo_dir&nbsp; = &quot;$PSEUDO_DIR&quot;,<br>&nbsp; outdir&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = &quot;$TMP_DIR&quot;,<br>/<br>&amp;SYSTEM<br>&nbsp; ibrav&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 6,<br>&nbsp; celldm(1)&nbsp;&nbsp; = 5.3033D0,<br>&nbsp; celldm(3)&nbsp;&nbsp; = 8.D0,<br>&nbsp; nat&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 7,<br>&nbsp; ntyp&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = 1,<br>
&nbsp; ecutwfc&nbsp;&nbsp;&nbsp;&nbsp; = 12.D0,<br>&nbsp; occupations = &quot;smearing&quot;,<br>&nbsp; smearing&nbsp;&nbsp;&nbsp; = &quot;methfessel-paxton&quot;,<br>&nbsp; degauss&nbsp;&nbsp;&nbsp;&nbsp; = 0.05D0,<br>/<br>&amp;ELECTRONS<br>&nbsp; conv_thr&nbsp;&nbsp;&nbsp; = 1.D-7,<br>&nbsp; mixing_beta = 0.3D0,<br>/<br>
&amp;IONS<br><b>&nbsp; ion_dynamics&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; = &quot;damp&quot;,</b><br>&nbsp; pot_extrapolation = &quot;second_order&quot;,<br>&nbsp; wfc_extrapolation = &quot;second_order&quot;,<br>/<br><br>Is the &quot;dt&quot; necessory for the &quot;ion_dynamics=damp&quot; ? And how to determine the value of &quot;dt&quot;?<br>
<br>Thanks.<br>