On Sat, 2014-08-30 at 03:33 -0400, Cameron Foss wrote: > Are the K_POINTS in the scf calculation for pw.x responsible for > specifying some relevant shape? (eg 4 4 4 or 8 8 8 = bulk material, > and 4 4 1 or 8 8 2 = thin film/2D structure)
I would say that it is the other way round: the shape of the cell determines the k-point grid P. > > > To put this in context, I am trying to measure the effects of Strain > on phonons and crystal structure of thin films of silicon stretched > over some SiGe Alloy or Ge substrate. The result being a stretched > layer of silicon over the substrate which is stretched in the 100 and > 010 directions, and negligibly compressed in the 001 direction. It is > important that the structure does not relax at all in the calculation > for this would give misleading results. > > > Thus far i have been using K_POINTS such as 4 4 4 or 8 8 8, and am > curious to know if these K_POINTS are meant for specifying bulk > materials, and if I should change to something more like 4 4 1 or 8 8 > 2 for thin filmed structures? > > > Best Regards, > Cameron > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum
