Hi Hakim, Perhaps, if you send your fdf file, it will be more easier to help. Reza
On 11/14/12, Abraham Hmiel <[email protected]> wrote: > Hakkim, > > SIESTA will automatically detect the molecule, chain, slab, or bulk type > depending on how close the images of each atom are across the x, y, and z > dimensions of your simulation cell. This is done in the shaper.f > subroutine. If your unit cell is big enough in all 3 dimensions such that > no orbitals interact (in a certain range) in your atom list's periodic > image, you will have a molecule. If they interact in one dimension, you > will have a chain (or nanowire), two, a slab, and all three dimensions, a > bulk system. > > If you are seeking to do a force minimization calculation on a bulk system > and you are getting "System type = molecule" in the output, you need to > check the dimensions of your unit cell to make sure it is small enough that > image atoms in all three dimensions will interact with the atoms whose > position you've explicitly declared in the unit cell. Maybe your dimensions > are proportionally correct to the crystal you'd like to simulate but your > lattice constant is too big. > > On Wed, Nov 14, 2012 at 9:36 AM, Hakkim Vovusha < > [email protected]> wrote: > >> HI, >> >> I am doing force minimization calculation (periodic system) in siesta and >> I have found in the output Siesta: System type = molecule but i need to >> change the molecule into bulk i.e. Siesta: System type = bulk. Can any >> one >> help how to change these molecule into bulk. >> >> with regards >> hakkim >> > > > > -- > *Abraham Hmiel* > Katherine Belz Groves Fellow in Nanoscience > Xue Group, College of Nanoscale Science and Engineering at SUNY Albany > http://abehmiel.net/about > -- Professor M. R. Benam, PhD Head of Physics Department , Payame-Noor University, Mashhad, Iran.
