[Pw_forum] "Centering" Requirement of ESM

[大谷実]

Dear Robert,

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.


Also requires symmetry checking to be
     disabled along z, either by setting nosym<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#nosym> = .TRUE.
     or by very slight displacement (i.e., 5e-4 a.u.)
     of the slab along z.


Best regard,
Minoru
--------------------------------------------------------------------------------------------------------
Minoru Otani
National Institute of Advanced Industrial Science and Technology
Research Centre for Computational Design of Advanced Functional Materials
email : minoru.otani at aist.go.jp<mailto:minoru.otani at aist.go.jp>
---------------------------------------------------------------------------------------------------------

On Jul 29, 2017, at 5:15, Lorenzo Paulatto <lorenzo.paulatto at impmc.upmc.fr> wrote:

It does not matter, it is only need to be roughly centered

--
Lorenzo Paulatto
Written on a virtual keyboard with real fingers

On 28 Jul 2017 9:36 p.m., "Dr. Robert Molt Jr." <r.molt.chemical.physics at gmail.com<mailto:r.molt.chemical.physics at gmail.com>> wrote:

Good evening,

I am confused by the "centering" requirements of ESM. It is stated that:

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 nosym<http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#nosym> = .TRUE.
     or by very slight displacement (i.e., 5e-4 a.u.)
     of the slab along z.


I have constructed a slab which is symmetric about the xy plane and centered around z=0 contour. This is fine and good.

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?


_______________________________________________
Pw_forum mailing list
Pw_forum at pwscf.org<mailto:Pw_forum at pwscf.org>
http://pwscf.org/mailman/listinfo/pw_forum
_______________________________________________
Pw_forum mailing list
Pw_forum at pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170728/f7fd2fe8/attachment.html>