[Pw_forum] Do we need to saturate the dangling bonds? and how to add vacuum?

[Sclauzero Gabriele]

You can "add" vacuum by increasing the cell size along z. In the ibrav=4 case this can be accomplished by increasing the celldm(3) parameter by a suitable amount. See also here:
http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#idp82000

HTH

GS





Sir, I am unable to understand how to add VACUUM in the input file of PWscf. While using PWGUI, I need to enter cell parameters only when ibrav=0. Here I understand that I could add vacuum in z-direction. But if I use ibrav=4, then I am only supposed to add atomic positions. This is what I am unable to understand. How do I enter vacuum in this case.
I use AVOGADRO to draw the geometry.
Any help would be welcomed.

Kind Regards,



Dr. Gabriele Sclauzero
Materials Theory - ETHZ
ETH Zurich, HIT G 43.2
Wolfgang-Pauli-Str. 27
8093 Zürich, Switzerland

Phone +41 44 633 94 10
Fax +41 44 633 14 59
gabriele.sclauzero at mat.ethz.ch<mailto:gabriele.sclauzero at mat.ethz.ch>
www.theory.mat.ethz.ch