<div dir="auto"><span style="font-family:sans-serif;font-size:13.696px">It doesn't require symmetry: it requires NO symmetry. Which is actually the opposite of what you seem to think. </span><div dir="auto" style="font-family:sans-serif;font-size:13.696px"><br></div><div dir="auto" style="font-family:sans-serif;font-size:13.696px">Kind regards </div><br><div data-smartmail="gmail_signature">-- <br>Lorenzo Paulatto<br>Written on a virtual keyboard with real fingers</div></div><div class="gmail_extra"><br><div class="gmail_quote">On 29 Jul 2017 2:14 p.m., "Robert Molt" <<a href="mailto:r.molt.chemical.physics@gmail.com">r.molt.chemical.physics@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<p>I appreciate the help. If ESM does not require this symmetry, can
you explain what is meant by the manual's statement of:</p>
<p>:</p>
<p>"<font color="#ff0000">Requires cell with a_3 lattice vector
along z,
</font></p>
<pre style="font-size:14px;color:rgb(0,0,0);font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:-webkit-left;text-indent:0px;text-transform:none;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;margin-top:0em"><font color="#ff0000"> normal to the xy plane, with the slab centered
around z=0</font>. Also requires symmetry checking to be
disabled along z, either by setting <a href="http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#nosym" target="_blank">nosym</a> = .TRUE.
or by very slight displacement (i.e., 5e-4 a.u.)
of the slab along z."
</pre>
<p>I want to make sure I am in compliance with the manual's
specifications, and I clearly must not understand what that means
if I misinterpreted it to mean it requires symmetry along the z
axis.</p>
<p><br>
</p>
<p>Separately, given that we have no symmetry in xy, is it logically
necessary to "cap" boundary atoms with hydrogens (or the like) to
avoid artifacts at the boundary?<br>
</p>
<pre style="font-size:14px;color:rgb(0,0,0);font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:-webkit-left;text-indent:0px;text-transform:none;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;margin-top:0em">
</pre>
<br>
<div class="m_9034486699484984519moz-cite-prefix">On 7/28/17 6:41 PM, 大谷実 wrote:<br>
</div>
<blockquote type="cite">
<div id="m_9034486699484984519divtagdefaultwrapper" style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif" dir="ltr">
<div dir="auto" style="word-wrap:break-word">Dear
Robert,
<div><br>
</div>
<div>Besides Lorenzo’s message, I can add one more
thing. ESM does not require symmetry along z-axis, so you do
not need to put an additional adsorbate molecule on the
bottom. </div>
<div><br>
</div>
<div>
<blockquote type="cite">
<div class="gmail_extra">
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<pre style="font-size:14px;background-color:rgb(255,255,255);margin-top:0em">Also requires symmetry checking to be
disabled along z, either by setting <a href="http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#nosym" target="_blank">nosym</a> = .TRUE.
or by very slight displacement (i.e., 5e-4 a.u.)
of the slab along z.</pre>
</div>
</blockquote>
</div>
</div>
</blockquote>
<div><br>
</div>
</div>
<div><br>
</div>
<div>Best regard,</div>
<div>Minoru</div>
<div>
<div>------------------------------<wbr>------------------------------<wbr>------------------------------<wbr>--------------</div>
<div>Minoru Otani</div>
<div>National Institute of Advanced Industrial
Science and Technology</div>
<div>Research Centre for Computational Design of
Advanced Functional Materials</div>
<div>email : <a href="mailto:minoru.otani@aist.go.jp" target="_blank">minoru.otani@aist.go.jp</a><br>
<div>------------------------------<wbr>------------------------------<wbr>------------------------------<wbr>---------------</div>
</div>
</div>
<div><br>
</div>
<div>
<div class="m_9034486699484984519AppleOriginalContents" style="direction:ltr">
<blockquote type="cite">
<div>On Jul 29, 2017, at 5:15, Lorenzo Paulatto
<a class="m_9034486699484984519moz-txt-link-rfc2396E" href="mailto:lorenzo.paulatto@impmc.upmc.fr" target="_blank"><lorenzo.paulatto@impmc.upmc.<wbr>fr></a> wrote:</div>
<br class="m_9034486699484984519Apple-interchange-newline">
<div>
<div dir="auto">It does not matter, it is
only need to be roughly centered <br>
<br>
<div>-- <br>
Lorenzo Paulatto<br>
Written on a virtual keyboard with real fingers</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On 28 Jul 2017 9:36 p.m.,
"Dr. Robert Molt Jr." <<a href="mailto:r.molt.chemical.physics@gmail.com" target="_blank">r.molt.chemical.physics@<wbr>gmail.com</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>Good evening,</p>
<p>I am confused by the "centering"
requirements of ESM. It is stated that:</p>
<pre style="font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;word-spacing:0px;background-color:rgb(255,255,255);margin-top:0em">Requires cell with a_3 lattice vector along z,
normal to the xy plane, with the slab centered
around z=0. Also requires symmetry checking to be
disabled along z, either by setting <a href="http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#nosym" target="_blank">nosym</a> = .TRUE.
or by very slight displacement (i.e., 5e-4 a.u.)
of the slab along z.
</pre>
<p>I have constructed a slab which is
symmetric about the xy plane and centered
around z=0 contour. This is fine and good.</p>
<p>However, once I add the adsorbate
molecule, I cannot have symmetry...unless it
is intended that I add the same adsorbate
molecule on the "bottom" of the simulation,
too? I am unclear what is meant by the slab
being "centered." Center of mass? Center of
symmetry?<br>
</p>
<p><br>
</p>
</div>
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