Dear all I will here give information about the tbtrans versions. First of all there exists 2 different versions of tbtrans from trunk-424 and onwards.
1. tbtrans version from siesta-3.1 and trunk-424 (in Util/TBTrans) I have searched through the files and found no inconsistency. The current gets calculated on each spin component and showed for each spin component. In line 317/311 of tbtrans in siesta-3.1 and trunk-424 respectively, the loop of the spin start. However, the current variable gets initialized to 0 in line 521/515 respectively. So in that case there is no error. It is the current for each spin. 2. tbtrans_rep (my version) only from trunk-424 and trunk-427 (in Util/TBTrans_rep) Yes, here there is an error. However, the error is not that it is the total current. The error is that after the first spin we get (below Current_spin[i] is the correctly calculated spin current) Current = Current_spin1 After the second spin we get Current = Current_spin1*38.73*1e-6*13.6058 + Current_spin2 Thus tbtrans_rep should have shown Current_spin2. So to find the correct Current_spin2 we find: Current_spin2 = Current - Current_spin1*5.26952634e-4 The spin part in the tbtrans_rep has some errors Yes, this is wrong and I have submitted a patch for the tbtrans_rep. Thanks a lot for noticing it. In this context I also discovered another error related to the spin. This error was exactly what you mentioned. The averaged files for spin is the accumulated transmission, TDOS and PDOS. Here it is a simple manner of subtracting the two. If in doubt please contact me. I have attached a patch that should be applied to the siesta-trunk-427 version. Kind regards Nick 2012/12/12 <[email protected]> > Dear Dr. Andersen, > > We are running spin polarized calculations at finite bias with the tbtrans > version from siesta 3.1. In the tbtrans output there is a line for the Spin > Up current as well as a line at the end of the file with another current > value. We initially thought that the second values was the Spin Down > current; however, we now think that this second value is actually the total > current (Spin Up + Spin Down). Could you please confirm if this is the > case, that is: is second current value in the output file is indeed the > total current? > > Looking closely at the tbtrans.F routine from both the siesta 3.1 tbtrans > as well as the trunk-424 tbtrans, it seems that indeed, the current values > is set to 0 outside the spin loop, so that for the second spin value (Spin > Down) the current in not reset to 0. This is however not documented in the > manual and it seems to us a bit awkward programming. > > Best regards, > > Diana M. Otálvaro > Doctoral Candidate > Computational Material Science > MESA+ Institute for Nanotechnology > University of Twente > Enschede, Nederland > [email protected] > > > > >
tbtrans_rep_427.patch
Description: Binary data
