<div dir="ltr"><div class="gmail_default" style="font-family:georgia,serif;font-size:small"><div class="gmail_default">Dear all,</div><div class="gmail_default" style="font-family:arial,sans-serif;font-size:12.800000190734863px">
<div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">I'm sorry to interrupt you.</font></div><div class="gmail_default"><font face="georgia, serif"><br>
</font></div><div class="gmail_default"><font face="georgia, serif">I'm new to QE. Recently, I'd like to do DFT calculation regarding hydrogen absorption on FeO(111) surface. </font></div><div class="gmail_default">
<font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">A small slab model with 4 layers (two layers for O while the other two for Fe and 1 atom in 1 layer) is established with O terminated. Hydrogen molecule is placed about 2 A above O top site with parallel direction. </font><span style="font-family:georgia,serif">The input file is shown below.</span></div>
<div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">However, the hydrogen molecule is move away from the surface during the relax calcuation. Could you give me some suggestion on my work?</font></div>
<div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">PS1: A some large slab model (4 atoms in 1 layer) is also established and used for calculation, but the results are the same.</font></div>
<div class="gmail_default"><font face="georgia, serif">PS2: The non-polarized calculation make great influence on the absorption of H2 on the surface? If the spin-polarized DFT is required for the calculation, is there any suggestion on the input file?</font></div>
<div class="gmail_default"><br></div><div class="gmail_default"><font face="georgia, serif">Also I 'm confused by a problem. </font></div><div class="gmail_default"><font face="georgia, serif">The initial atoms position of the slab surface model (Structure A), is relax to Structure B.</font></div>
<div class="gmail_default"><font face="georgia, serif">If the 'relax' calculation is implemented for slab surface and absorption atoms (hydrogen molecule in my case), the atom position of slab surface in the input file should be Structure A or B? Is there any difference between the two choices?</font></div>
<div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">Thanks for your time and patience in advance.</font></div><div class="gmail_default"><font face="georgia, serif"><br>
</font></div><div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">-------------------------------------------</font></div><div class="gmail_default">
<font face="georgia, serif">cat > <a href="http://feo111.relax.in/" target="_blank">feo111.relax.in</a> << EOF</font></div><div class="gmail_default"><font face="georgia, serif">&CONTROL</font></div><div class="gmail_default">
<font face="georgia, serif"> calculation = "relax",</font></div><div class="gmail_default"><font face="georgia, serif"> prefix = "feo111",</font></div><div class="gmail_default"><font face="georgia, serif"> pseudo_dir = "$PSEUDO_DIR",</font></div>
<div class="gmail_default"><font face="georgia, serif"> outdir = "$TMP_DIR",</font></div><div class="gmail_default"><font face="georgia, serif">/</font></div><div class="gmail_default"><font face="georgia, serif"><br>
</font></div><div class="gmail_default"><font face="georgia, serif">&SYSTEM</font></div><div class="gmail_default"><font face="georgia, serif"> ibrav = 14,</font></div><div class="gmail_default"><font face="georgia, serif"> celldm(1) = 5.79,</font></div>
<div class="gmail_default"><font face="georgia, serif"> celldm(2) = 1.0,</font></div><div class="gmail_default"><font face="georgia, serif"> celldm(3) = 4.5,</font></div><div class="gmail_default"><font face="georgia, serif"> celldm(4) = 0.0,</font></div>
<div class="gmail_default"><font face="georgia, serif"> celldm(5) = 0.0,</font></div><div class="gmail_default"><font face="georgia, serif"> celldm(6) = -0.5,</font></div><div class="gmail_default"><font face="georgia, serif"> nat = 6,</font></div>
<div class="gmail_default"><font face="georgia, serif"> ntyp = 3,</font></div><div class="gmail_default"><font face="georgia, serif"> ecutwfc = 25.0,</font></div><div class="gmail_default"><font face="georgia, serif"> occupations = 'smearing',</font></div>
<div class="gmail_default"><font face="georgia, serif"> smearing = 'marzari-vanderbilt',</font></div><div class="gmail_default"><font face="georgia, serif"> degauss = 0.01</font></div><div class="gmail_default">
<font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">/</font></div><div class="gmail_default"><font face="georgia, serif">&ELECTRONS</font></div><div class="gmail_default">
<font face="georgia, serif"> conv_thr = 1.D-7,</font></div><div class="gmail_default"><font face="georgia, serif"> mixing_beta = 0.7,</font></div><div class="gmail_default"><font face="georgia, serif"><br></font></div>
<div class="gmail_default"><font face="georgia, serif">/</font></div><div class="gmail_default"><font face="georgia, serif">&IONS</font></div><div class="gmail_default"><font face="georgia, serif">/</font></div><div class="gmail_default">
<font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">ATOMIC_SPECIES</font></div><div class="gmail_default"><font face="georgia, serif"> Fe 55.845 Fe.pbe-nd-rrkjus.UPF</font></div>
<div class="gmail_default"><font face="georgia, serif"> O 15.999 O.pbe-rrkjus.UPF</font></div><div class="gmail_default"><font face="georgia, serif"> H 1.00794 H.pbe-rrkjus.UPF</font></div><div class="gmail_default"><font face="georgia, serif"><br>
</font></div><div class="gmail_default"><font face="georgia, serif">ATOMIC_POSITIONS {crystal}</font></div><div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">O 0.666654 0.333327 0.272813</font></div>
<div class="gmail_default"><font face="georgia, serif">O 0.333321 0.666660 0.090938</font></div><div class="gmail_default"><font face="georgia, serif">Fe 0.666654 0.333327 0.000000</font></div><div class="gmail_default">
<font face="georgia, serif">Fe 0.999987 0.999994 0.181875</font></div><div class="gmail_default"><font face="georgia, serif">H 0.789366 0.333327 0.422813</font></div><div class="gmail_default"><font face="georgia, serif">H 0.543942 0.333327 0.422813</font></div>
<div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif"><br></font></div><div class="gmail_default"><font face="georgia, serif">K_POINTS {automatic}</font></div>
<div class="gmail_default"><font face="georgia, serif">4 4 1 0 0 0</font></div></div><div class="gmail_default"><br></div><div class="gmail_default"><br></div><div class="gmail_default"><br></div><div class="gmail_default">
<br></div><div class="gmail_default"><br></div><div style="font-family:arial,sans-serif;font-size:12.800000190734863px"><div dir="ltr"><div><i>————</i><br></div><div><i><br></i></div><div><font face="georgia, serif"><div class="gmail_default" style="font-size:small;display:inline">
</div>Jian XU</font></div><div><font face="georgia, serif"><br></font><div><font face="georgia, serif"><div class="gmail_default" style="font-size:small;display:inline"></div></font><font face="georgia, serif"><div class="gmail_default" style="display:inline">
</div></font><span style="font-family:georgia,serif">College of Materials Science and Engineering</span><div><font face="georgia, serif">Faculty of Engineering, Chongqing University<br><div class="gmail_default" style="font-size:small;display:inline">
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