hello, Thanks for your reply, I think, I understand that you want to tell me. In this case, I have to optimise the 'a' and also 'c/a' variables and I need to know; For example a=b=9.6448 and c=4.2699(I obtained the tubegen), I will use
2010/5/5 Marcos Veríssimo Alves <[email protected]> > Erkan, > > If you multiply 24.9 by 0.1704, you get roughly the value of cell_length_c > that tubegen gives you. Now, I don't know what tubegen does, but the large > values of the lattice vectors in the ab plane are meant to give a good > distance between the tube and its images - siesta uses periodic boundary > conditions and the largest possible distance is necessary to avoid the above > mentioned interactions. > > Marcos > > On Wed, May 5, 2010 at 9:04 PM, Erkan Tetik <[email protected]> wrote: > >> Dear all, >> >> I want to calculate a cabon nanotube with siesta and I've tried the >> "nanotube-c-5-0" example that it is in the Tests folder in Siesta. But, I >> don't understand the LatticeVectors and LatticeConstant parameter in the fdf >> file for this calculation only. I use the "tubegen" program to generate >> anything carbon nanotube. For example, I'm getting the Atomic Coordinates >> and lattice constats for CNT(5,0) with tubegen, I mean; >> >> lattice constats(unit is Angs, tubegen out file); >> _cell_length_a 7.3128 >> _cell_length_b 7.3128 >> _cell_length_c 4.2806 >> >> in the nanotube-c-5-0.fdf file; >> LatticeConstant 24.9 Ang >> %block LatticeVectors >> 1.0 0.0000 0.0 >> -0.50 0.86602540378444 0.00 >> 0.0 0.0 0.1704 >> %endblock LatticeVectors >> >> I haven't obtained the LatticeConstant and LatticeVectors in the >> nanotube-c-5-0.fdf by using the lattice constats in the tubegen out file. I >> have been examined the siesta-3.0-b.pdf file, but, I could not find a >> solution yet. Please, could you explain to me? >> >> Best Regards. >> Erkan Tetik >> > >
