Mohammad an input file of siesta is where you will set the parameters to perform your calculations. You do not need exactly to "calculate" them, you must define them. You define them based on your target system, in this case the nanotube.
Think that your nanotube is trapped inside a box and this box will be repeated all over the space. The %block lattice vector command defines the size of this box with a set of 3 vectors as shown in the example you are looking at. Imagine your nanotube inside this box. The coordinates of the atoms themselves are specified below inside %block AtomicCoordinatesAndAtomicSpecies. And think that the lattice vector constant is simply a factor that multiplies the vectors which define your box. I recommend you to draw the vectors in a piece of paper and visualize this "imaginary" box as 25 Ang (lattice constant) larger... Then try to imagine the atoms of the carbon nanotube inside it. best CGRocha On 2 December 2011 10:18, Mohammad Goodarzi <[email protected]> wrote: > Dear CGRocha > > I would like to calculate all the following information for a nanotube, how > can I calculate it ? > for example how to calculate a LatticeConstant for a nanotube ? > how to calculate the block Latticevectors? it should be a matrix 3*3? why > and how to calculate it ? > it is matter if we doped for example Pt in nanotube? > > LatticeConstant ? Ang > > %block LatticeVectors > ? ? ? > ? ? ? > ? ? ? > %endblock LatticeVectors > > > Kind Regards > Mohammad > > > > > On Thu, Dec 1, 2011 at 10:21 PM, Gomes Rocha <[email protected]> wrote: >> >> What exactly you did not understand? >> >> CGRocha >> >> On 1 December 2011 17:07, Mohammad Goodarzi <[email protected]> >> wrote: >> > Dear >> > >> > I would like to calculate following parameters for a (8,0) doped Mg >> > nanotube, >> > but i can not, can anyone explain how to calculate this ? >> > >> > I saw that Marcos mention somthing like this , but i did not fully >> > understand >> > http://www.mail-archive.com/[email protected]/msg02462.html >> > >> > can anyone explain it ? >> > >> > LatticeConstant >> > >> > %block LatticeVectors >> > >> > %endblock LatticeVectors >> > >> > >> > Thanks > >
