On 08/02/2011 11:12 PM, Guangping Zhang wrote:
Dear Siesta users: I now have a puzzle on the k point sampling. Before, I usually use a cubic in real space, for example: %block LatticeVectors a 0.0 0.0 0.0 b 0.0 0.0 0.0 c %endblock LatticeVectors So its corresponding reciprocal space is also a cubic: a' 0.0 0.0 0.0 b' 0.0 0.0 0.0 c' when I use the k sampling for this kind cell %block kgrid_Monkhorst_Pack 4 0 0 0.0 0 4 0 0.0 0 0 1 0.0 %endblock kgrid_Monkhorst_Pack I think it means 4, 4 and 1 k point will be used along a', b' and c' will be used. (Am I right?) But if I use a non-cubic cell, for example: %block LatticeVectors a1 a2 0.0 b1 b2 0.0 0.0 0.0 c %endblock LatticeVectors so the corresponding reciprocal space is also a non-cubic: maybe like the following: a1' a2' a3' (say Vector1) b1' b2' b3' (say Vector2) c1' c2' c3' (say Vector3) If I also use a K point sampling like: %block kgrid_Monkhorst_Pack 4 0 0 0.0 0 4 0 0.0 0 0 1 0.0 %endblock kgrid_Monkhorst_Pack This time, are 4, 4 and 1 the k points along the reciprocal Vector1, Vector2 and Vector3 respectively? Maybe, my discription could make someone confused. In other words, is the block kgrid represented in real space lattice vectors or in reciprocal space vectors or just in cartesian coordinates? Any reply will be appreciated. Best Guangping 2011-08-03 ------------------------------------------------------------------------ Guangping Zhang
See here for some notes: http://cmt.dur.ac.uk/sjc/thesis_mcg/node24.html Regards -- Hongyi Zhao <[email protected]> Institute of Semiconductors, Chinese Academy of Sciences GnuPG DSA: 0xD108493
