[Pw_forum] Pressure along the z-direction of slab

[Paolo Giannozzi]

On Sun, 2012-11-18 at 19:21 -0800, loc duong ding wrote:

> I am trying to cell relax a slab structure (along z axis). What I expect is the pressure along z-direction ( diagonal term in pressure tensor) should be zero.  However, I see the value is about -20 kbar. 

please see points 6/10 amd 6.11 of the FAQ:
  http://www.quantum-espresso.org/?page_id=38
P.
-- 
Paolo Giannozzi, IOM-Democritos and University of Udine, Italy