Hi Peng, thanks for the answer. Actually I'm using silicon for the electrodes, that may not that efficient in screening like metals. I've verified that I get different AVTRANS plots when I change the cell side along z, or when I passivate the electrodes with hydrogens, or when I use a periodic structure (both left/right electrodes are bulk-Si).
Actually, the "starting charge density for transiesta" seems to influence the final AVTRANS. For this reason I cannot figure out what's the proper way to build the left+scat+right system. RG On mer 23 nov 2011, Yun-Peng Wang wrote: > In my opinion, the purpose of left+scat+right structure is to build a > starting charge density for transiesta run, especially charge density in > the scattering region. Due to good screening property of metals or other > conducting electrodes, the dangling bonds at ends of left+scat+right > structure influence little on charge density in the scattering region. > In transiesta run, the left+scat+right structure extend to > left(infty)+scat+right(infty), again the dangling bonds matter nothing. > Overall, I think inserting vacuum is an easy way to deal with different > left/right electrode problems. > > Yun-Peng > > On 11/23/2011 05:48 PM, Roberto Guerra wrote: > > Hello, > > > > I cannot figure out what's the correct way of setting up the > > scattering region in the case of electrodes made by different > > materials. After I do the calculation for the left and right > > electrodes, I build the system with left+scat+right regions. The > > problem is that in defining the cell size along z I have to introduce > > some vacuum between the replica, otherwise the electrodes will > > interact and change the results. But then I have to passivate the > > electrodes due to the dangling bonds! What's the proper way to treat > > different electrodes at the z boundary of the cell?
