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Well, as a matter of fact you could try to use the quantum-enthalpy
functional of Matteo Cococcioni et al. Phys. Rev. Lett. <b>94</b>,
145501<br>
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<a class="moz-txt-link-freetext" href="http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.94.145501">http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.94.145501</a><br>
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Please double check that this is something that may be useful for
your calculations. In case, the method is implemented in the CP
code, PRESS_AI namelist, but also in PW by exploiting the external
Environ module (which you would need to download and compile, more
details can be found here <a class="moz-txt-link-abbreviated" href="http://www.quantum-environment.org">www.quantum-environment.org</a>). The actual
release of Environ is compatible with QE 5.1, 5.1.1 and 5.1.2, if
you are using a more recent version I could let you have the patch.
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<br>
Oliviero Andreussi<br>
<br>
<div>Senior Postdoctoral Researcher</div>
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<p>École Polytechnique Fédérale de Lausanne (EPFL) and </p>
<p>Università della Svizzera Italiana (USI) of Lugano</p>
<p>Switzerland </p>
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<div class="moz-cite-prefix">On 10/28/2015 10:05 AM, Lorenzo
Paulatto wrote:<br>
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<blockquote cite="mid:2062297.1EgWCru8j5@naquite" type="cite">
<pre wrap="">On Wednesday, October 28, 2015 04:13:41 PM 李睿 wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Hello, everyone
I want to calculate molecules adsorption under 1Bar air pressure using
Pwscf. Can I add air pressure in it?
</pre>
</blockquote>
<pre wrap="">
No, you cannot. Gas pressure is a macroscopic variable. It does not exist in a
zero-temperature DFT calculation. You may do a molecular dynamics simulation
with a bunch of molecules at a certain temperature, but it is very impractical
and deducing the pressure from volume+temperature when the volume is so small
and includes a chemically reactive surface is not granted.
What you can do is to include its effect via a chemical potential, you can
find a brief explanation in chapter 3.2 of my PhD thesis
<a class="moz-txt-link-rfc2396E" href="http://urania.sissa.it/xmlui/bitstream/handle/1963/5363/paulatto_thesis.pdf?sequence=1&isAllowed=y"><http://urania.sissa.it/xmlui/bitstream/handle/1963/5363/paulatto_thesis.pdf?sequence=1&isAllowed=y></a>
(eq. 3.12 in particular, but read all the chapter). If I remember correctly, I
studied the problem on "Arthur W. Adamson, Physical Chemistry of Surfaces,
John Wiley and Sons, 1990", so if you can get a copy of the book you'll find a
better and longer explanation.
HTH
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