Kiarash, I think that using the expression given by Ruslan, you should have zero for the charge transfer once all the systems are, at the beginning, neutrals.
I you use the ideas from Abraham you should have how the charge is distributed (but given a zero total difference charge). If you want to know for an specific atom, you should look the atom charge before/after the interaction. []'s, @mps On Fri, Jul 26, 2013 at 10:09 AM, Abraham Hmiel <[email protected]> wrote: > Kiarash, > > To add to Ruslan's response, two and a half years ago on SIESTA-L there > was a correspondence between Gao Min and Martin Zoloff on how to create > charge density difference plots- > http://www.mail-archive.com/[email protected]/msg02700.html - Martin made a > fortran code for creating charge density difference plots from .RHO files. > It is quite useful and I find myself using it often. Just make sure you use > the same grid, system size, etc. for all 3 "pieces." > > Other options you can look into are Bader and Hirschfield charge analysis, > but I would definitely start with charge density difference. > > Cheers, > > -- > *Abraham Hmiel* > Katherine Belz Groves Fellow in Nanoscience > Xue Group, College of Nanoscale Science and Engineering at SUNY Albany > http://abehmiel.net/about > > On Fri, Jul 26, 2013 at 5:58 AM, Руслан Жачук <[email protected]> wrote: > >> The best way is to do like this: >> 1) Calculate charge density of isolated atom, n_at >> 2) Calculate charge density of another isolated system, which you are >> interested, for example, surface, n_surf >> 3) Calculate charge density of combined system , atom on the surface, >> n_combined >> >> Then charge transfer is: delta_n = n_combined - n_at - n_surf >> >> Check out PhysRevB 81, 165424 ( 2010 ) for details. >> >> Regards >> Ruslan Zhachuk >> >> >> >> 2013/7/26 Kiarash Hosseini <[email protected]> >> >>> Dear All, >>> Good time. >>> >>> I want to compute the charge transfer from an atom to the other in an >>> ensemble quantitatively. As far as I am concerned I have two choices: >>> >>> 1. Using Local Density of states (LDOS). >>> 2. Using *Mulliken population* analysis. >>> >>> Please let me know if any of the above mentioned options work? >>> Also please suggest any other way to compute charge transfer from among >>> specific atoms. >>> Thank you in advance. >>> >>> -- >>> Yours Sincerely, >>> Kiarash Hosseini >>> Mechanical Engineering MSc >>> Tehran >>> Iran >>> >> >> > > > > >
