In data 21 agosto 2009 alle ore 11:22:20, ali kazempour <kazempoor2000 at yahoo.com> ha scritto:
> Dear all > In principle ,where the shift of kpoints is important? I mean which > information should we loose when we don't use from shift in our kpoint > mesh? You don't loose any information, it's just that a shifted grid makes the calculation converge faster w.r.t the number of kpoints. This is normally only true after applying symmetry operation to reduce the number of kpoints. > [...] does it mean that symmetry reduces this set to a set of points in > the irreducible part of BZ? Exactly. There are some exceptions though, e.g. using Gamma point (and only Gamma point) is the only meaningful choice for isolated systems. regards -- Lorenzo Paulatto SISSA & DEMOCRITOS (Trieste) phone: +39 040 3787 511 skype: paulatz www: http://people.sissa.it/~paulatto/ *** save italian brains *** http://saveitalianbrains.wordpress.com/
