Transmission, total current, and conductance

At first, openmx calculates the transmission, the total current, and the conductance. The relevant keywords for the calculation are as follows:

    NEGF.tran.Analysis         on        #  default on
    NEGF.tran.CurrentDensity   on        #  default on
    NEGF.tran.energyrange -10 10 1.0e-3  # default=-10.0 10.0 1.0e-3 (eV)
    NEGF.tran.energydiv        200       # default=200
    NEGF.tran.Kgrid            1 1       # default= 1 1

In the calculations of the transmission, the current, and the conductance, following messages are printed in the standard output.

*******************************************************
*******************************************************
 Welcome to TRAN_Main_Analysis.                        
 This is a post-processing code of OpenMX to analyze   
 transport properties such as electronic transmission, 
 current, eigen channel, and current distribution in   
 real space based on NEGF.                             
 Copyright (C), 2002-2015, H. Kino and T. Ozaki        
 TRAN_Main_Analysis comes with ABSOLUTELY NO WARRANTY. 
 This is free software, and you are welcome to         
 redistribute it under the constitution of the GNU-GPL.
*******************************************************
*******************************************************


Chemical potentials used in the SCF calculation
  Left lead:  -5.125617225230 (eV)
  Right lead: -5.125617225230 (eV)
NEGF.current.energy.step 1.0000e-02 seems to be large for the calculation of current ...
The recommended Tran.current.energy.step is 0.0000e+00 (eV).
  TRAN_Channel_kpoint  0    0.000000    0.000000
  TRAN_Channel_energy  0    0.000000 eV
  TRAN_Channel_Num 5 

Parameters for the calculation of the current
  lower bound:     -5.125617225230 (eV)
  upper bound:     -5.125617225230 (eV)
  energy step:      0.010000000000 (eV)
  imaginary energy  0.001000000000 (eV)
  number of steps:   0         

  calculating...

  myid0= 0 i2= 0 i3= 0  k2=  0.0000 k3= -0.0000
  myid0= 1 i2= 0 i3= 0  k2=  0.0000 k3= -0.0000

Transmission:  files

  ./negf-chain.tran0_0

Current:  file

  ./negf-chain.current


Conductance:  file

  ./negf-chain.conductance


After the calculations, in this case you will obtain three files negf-chain.tran0_0, negf-chain.current,
negf-chain.conductance:

As an example, the k-resolved transmission drawn by using the file 'System.Name.conductance' is shown in Fig. 41.


Figure 41: k-resolved transmission at the chemical potential for (a) the majority spin state of the parallel configuration, (b) the minority spin state of the parallel configuration, and (c) a spin state of the antiparallel configuration of Fe$\vert$MgO$\vert$Fe, respectively. For the calculations k-points of $120\times 120$ were used.
\includegraphics[width=8.0cm]{NEGF_MgO.eps}