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Messages - guyue03

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1
Hi,

I am using the ATK 17 and I have gotten some finite-bias transmission spectrums.  Actually, I need to get the current value at a certain bias.  How can I get the current value from the hdf5 file( for example:ivcurve_selfconsistent_configuration_-0.05000V.hdf5)

I just forgot to use IV Curve to calculate the current. What should I do now?

BTW, I have low-spin state and high-spin state configuration. For high-spin state, I need spin-up  and spin-down current. For low-spin state, I need one current value. 

Thanks so much!

2
Okay, thanks! I will try this later. And I am confused about another problem. For example, at 0.3V,  it is converged. But at 0.1V, it does not be converged. I wonder why the SCF can be converged at a larger bias, rather than a smaller one? I mean it may be like this trend: 0.1V(success), 02V(success), 0.3V(success), and 0.4V(fail). Now, I have this: 0.1V(fail), 02V(success), 0.3V(success), and 0.4V(fail)

3
Hi,

  How to solve the convergence problem when doing IV calculation?  SCF cannot be converged at 0.4  and 0.5V. (0.3V is okay) I have read the https://docs.quantumwise.com/technicalnotes/negf_convergence_guide/negf_convergence_guide.html#negf-convergence-guide-pulay
carefully. First,   I increase the parameter Maximum steps to 250. (fail). Since I find dE and dH became oscillated. Then I  just decrease the Damping factor to 0.01 and increase the number of History steps to 35. (still fail) I also try to increase the k-sampling factor a bit. (fail as well)
  What am I supposed to do now?

Thank you so much!

4
Hi,

  I've followed your guidance to compute the dE. I am faced with a new problem now. I have attached all files, including the error, and py files. Could you help me?
  Thank you so much!!!!

5
Hi,

  If I have computed the dE, then is that mean I could get the energy jump at the interface, as shown in the picture?
  Thank you!

6
Hi,
 
  I wonder how to calculate the change in the electrostatic energy. I've already done a script to calculate the electrostatic potential of the device, but an error occurred "The parameter 'configuration' must be an instance of one of the following: BulkConfiguration, MoleculeConfiguration".
  My goal is to draw a picture like the following picture.
  Can you help me solve this problem?

7
Thank you! I've solved this problem.

8
Hi,
 
  Here is my problem. How can I calculate the excess electrons in the center magnetic Fe atom (NFe)and in 3d orbitals of the Fe atom(N3d)?

  By the way, I've got the total magnetic moment  by following the script:
# -------------------------------------------------------------
# Mulliken population
# -------------------------------------------------------------
mulliken_population = MullikenPopulation(bulk_configuration)
nlsave('magnetic_hs.nc', mulliken_population)
nlprint(mulliken_population)

# Majority and minority populations
popUp = mulliken_population.atoms(Spin.Up)
popDown = mulliken_population.atoms(Spin.Down)

# Magnetic moments
moments = popUp - popDown

print "Individual magnetic moments"
for i in range(len(moments)):
    print  i , moments

# Calculate total magnetic moment / unit cell.
mag_mom =  (popUp.sum() -  popDown.sum())

print
print "Total magnetic moment / unit cell"
print mag_mom

10
Hi,
  Here is my problem. The  SCF can't be converged when calculating zero-bias transmission in MTJ device by using ATK 17. However, SCF is finished when using ATK 13.
  Could you tell me how to solve this problem? I want to do the calculation with ATK 17. The file is attached.

Thank you so much!

11
General Questions and Answers / Re: TMR calculation
« on: November 6, 2018, 05:08 »
For i in range(0,201):
    transmission_para = nlread('mgo_para.nc', TransmissionSpectrum)[ i ]

I got err "index out of range". How can I do to deal with TransmissionSpectrum with energy (-1,1,201)

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