Edroaldo, The components of the lattice vectors
ai=LatticConstant*(aix,aiy,aiz), i=1,2,3 in the example for the (5,0) nanotube are such that you have a triangular lattice in the xy plane with vectors 25 Angstroms long, and the third vector is much shorter that the ones in the xy plane. Therefore, your tube would be directed along the z axis, and separated from its periodic images by 25 Angstroms. No need to get computer software for that, just plain old Kittel or Ashcroft :) Marcos On Tue, Dec 28, 2010 at 12:28 PM, Edroaldo Lummertz da Rocha < [email protected]> wrote: > Hello, I am a beginner in SIESTA and Carbon Nanotubes and would like to > know if someone could me give some direction. I have searched in Carbon > Nanotubes literature about the Lattice Vectors of this structures but I can > not see a relationship between this and the LatticeVectors block that I need > define to SIESTA execution, especially in the SIESTA Carbon Nanotube (5,0) > example in the /Tests folder of SIESTA, for example: > > LatticeConstant 25.0 Ang # Lattice constant alat > %block LatticeVectors # Lattice vectors, in units of alat > 1.0 0.0000 0.0 > -0.50 0.86602540378444 0.00 > 0.0 0.0 0.1704 # distance along z ==> dCC=1.42 AA > %endblock LatticeVectors > > How can I get this LatticeVectors? Is it calculated from a software? I am > sorry if this is redundant, but I could not find this information yet. Any > direction will be very usefull. Thanks so much. > > >
