2014-04-30 18:47 GMT+00:00 zehab sohbatzadeh <[email protected]>: > Dear Nick Papior Andersen > Very thanks from your reply. > 1)My electrods geometry is same but their magnetization are not same,again > in this case buffer atoms are necessary? > I would suspect so. If both your semi-infinite lead have different magnetization then your electrodes are most likely not behaving like bulk without buffer atoms. Consider that the initial siesta calculation is the left+device+right in the periodic picture. Hence, if the electrodes are different then you are finding the electrode electronic structure of an interface-region and not bulk.
> 2) Can i get buffer atoms when their magnetization is different and ignore > them when they are same or i can get them in two cases. > As stated in my previous mail. When your electrode atoms behaves like bulk in you system, then you don't need buffer atoms. I suggest you to test it for your system. > 3)when i get buffer atoms computing time became very long.it is big > problem for me. > best wishes > Hopefully only the siesta part of the calculation takes longer? If your device region+electrode atoms are constant, then the computing time for the transiesta part, should more or less be the constant. > > > Zihab Sohbatzadeh, > PhD Student, > Dept. of Physics, > Faculty of Science, > Ferdowsi University of Mashhad , > Mashhad , > Iran . > Mobile: +98 9153490795 > Phone: +98 511 8818534 > Fax : +98 511 8796416 > On Wednesday, April 30, 2014 9:45 PM, Nick Papior Andersen < > [email protected]> wrote: > You need to consider the electrodes to behave as bulk electrodes. If > they don't, then your calculation will most likely be wrong. > > So if you have different species in your electrodes (or different > geometries), then yes. I would start with converging the amount of > buffer-atoms needed. > > To ease the convergence I would recommend that you take a partial system > which is as small as you can make it. > > > > 2014-04-29 17:35 GMT+00:00 zehab sohbatzadeh <[email protected]>: > > Hi dear *users* > Is it possible ignore buffer atoms although when electrodes are > different or it is necessary. > best regards > > > > Zihab Sohbatzadeh, > PhD Student, > Dept. of Physics, > Faculty of Science, > Ferdowsi University of Mashhad , > Mashhad , > Iran . > Mobile: +98 9153490795 > Phone: +98 511 8818534 > Fax : +98 511 8796416 > > > > > -- > Kind regards Nick > > > -- Kind regards Nick
