many many thanks to you Camps...
On Fri, Feb 7, 2014 at 10:01 PM, I. Camps <[email protected]> wrote: > Suman, > > What I use to do is to transform (rotate/translate) the XYZ coordinates of > my system in such a way that the central point of it correspond with the > point (a/2, b/2, c/2). Where a, b and c are the fake lattice parameters. > These lattice parameters have to be big enough to avoid disk-disk > interaction. This "big enough" could be determined by calculating the > system energy for different values of the lattice parameters. When the > system energy become lattices independent, that are your 'big enough" > values. > > In your case, as you have a disk (of radii R and width r, for example), > you can start with lattice parameters a=b=c=2R. This is the easy way where > you have the same lattice size in three directions. This can imply a waste > of resource. As R >> r, the lattice parameter perpendicular to the plane do > not need to be the same as in the other two directions. > > An important point is that the coordinates must be Cartesian. If you use > fractional coordinates, the atoms position will scale as you change your > lattice coordinates. > > > []'s, > > @mps > > > On Fri, Feb 7, 2014 at 1:54 PM, Suman Chowdhury < > [email protected]> wrote: > >> Thanks to all.Can you tell me how I put "fake boundary condition" i.e. >> putting the nano disk in a large enough box.. >> >> >> On Fri, Feb 7, 2014 at 9:11 PM, Bailey, Steven >> <[email protected]>wrote: >> >>> Taking the isolated disc will give you the energy levels (flat). You >>> need to connect the disc to periodic leads or make the discs periodic to >>> obtain the band structure of your system. >>> >>> >>> >>> Dr S Bailey >>> >>> Department of Physics >>> >>> Lancaster University UK >>> >>> Email: [email protected] >>> >>> Tel: +441524592844 >>> >>> >>> >>> *From:* [email protected] [mailto:[email protected]] *On >>> Behalf Of *Suman Chowdhury >>> *Sent:* 07 February 2014 15:19 >>> *To:* [email protected] >>> *Subject:* [SIESTA-L] Nanodisks >>> >>> >>> >>> Dear all, >>> >>> How do I calculate the electronic structure of graphene nano disks which >>> do not have any boundary condition by siesta? >>> >>> >>> >>> -- >>> >>> >>> >>> >>> *Junior research fellow Dept. of Physics, University of Calcutta >>> Kolkata- 700009, West Bengal, India.* >>> >>> * Ph no-+91-9830512232 <%2B91-9830512232>* >>> >>> >>> >> >> >> >> -- >> >> >> >> *Junior research fellow Dept. of Physics, University of >> Calcutta Kolkata- 700009, West Bengal, India.* >> * Ph no-+91-9830512232 <%2B91-9830512232>* >> >> > -- *Junior research fellow Dept. of Physics, University of Calcutta Kolkata- 700009, West Bengal, India.* * Ph no-+91-9830512232*
