Thank you!
It helps. I was confuse if it has effect
on my calculation when I use shift 0.5 0.5 0.5.
Yes, my 1D crystal is along z-direction!
Thank you!
Yaroslav Shtogun
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From: Michel Côté
[mailto:michel.cote@umontreal.ca]
Sent: Monday, March 27, 2006 3:58
PM
To: forum@abinit.org
Subject: Re: [abinit-forum] shiftk
for 1D crystal?
Hello Yaroslav,
For a 1D system, there is no dispersion in the other 2 directions and therefore
there is no need to sample those direction and I guess that is the reason you
have a sampling 114. Your 1D system is along the z-direction?
Because there is no dispersion, there is no need to shift along those
directions. So you can use the shiftk 0.0 0.0 0.5 . Note that it would not
matter if you had shifted the grid, but is it just more consistent. The only
point that you need to be careful is for a possible Peierl’s deformation, and
often you need not shift the k-points in order for this deformation to happen
in DFT.
Hope this help,
Michel
Le 26/03/06 20:04, « yshtogun@cas.usf.edu »
<yshtogun@cas.usf.edu> a écrit :
Dear abinit users!
I have question about shiftk. Tutorial and manual said that‰ When the
primitive vectors of the lattice do NOT form a FCC or a BCC lattice, the usual
(shifted) Monkhorst-Pack grids are formed by using nshiftk=1 and shiftk 0.5 0.5
0.5‰. I tray calculate energy for my 1D crystal, I used ngkpt 1 1 4 but I
am confuse about the value of shiftk.
Is the value of shiftk the same for 1D crystal like for 3D? I mean
can I use default value for 1D calculation.
Thank you
Yaroslav!
--
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Michel Cote
tel:
+1 (514) 343-5628
Professeur agrégé
fax:
+1 (514) 343-2071
Département de physique
Université de Montréal
C.P. 6128, succ. Centre-ville
Montréal (Québec) H3C 3J7
Michel.Cote@umontreal.ca
Canada
www.phys.umontreal.ca/~michel_cote
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