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 Z?rich, 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
