Messages

1

General Questions and Answers / Re: Does not "device extended huckel calculator " support spin?

« on: August 26, 2011, 09:22 »

Oh.....  
Thank you for your response.
At first, I will try other method.

2

General Questions and Answers / Re: parameter for Extended Huckel Theory

« on: August 26, 2011, 09:19 »

Thank you for your help~

3

General Questions and Answers / Does not "device extended huckel calculator " support spin?

« on: August 25, 2011, 08:48 »

Dear all,

I want to calculate MTJ structure by using EHT.
but... When I run script,
ATK program said "The DeviceHuckelCalculator does not suppot spin"..

Is there no method to run spin polarized EHT calculation?

Thanks.

4

General Questions and Answers / parameter for Extended Huckel Theory

« on: August 25, 2011, 07:58 »

Dear all,

I want to modify EHT parameter to get more accurate result.
But, paramters make me confusing.
In short, is 'ionization_potential' in ATK parameter is 'onsite energy' of EHT?




* reference parameter: E_onsite, ζ1, c1, ζ2, c2 (On site energy, exponents, coefficients) for each orbital.
* ATK parameter:  ionization_potential, wolfsberg_helmholtz_constant, onsite_hartree_shift, vcuum_level, principal_quantum_number, angular_momentum, slater_coefficients, weights  

I think exponents ζ =  slater_coefficients, coefficients c = weights
and then... What is 'E_onsite'?

The name 'onsite_hartree_shift' is similar. but it's only for elements, not orbitals.
May be, ionization_potential is onsite energy.
But I'm not sure. Am I right?


Thanks,

5

General Questions and Answers / How to calculate upspin/dnspin current of AP/P state?

« on: August 1, 2011, 08:02 »

Dear all,

I want to get upspin/dnspin current to calculate spin transfer torque.
(T||(theta) = hbar/2e*sin(theta)*(I_ap*P_ap-I_p*P_p)/2, I=current, P=polarization, ap=anti parallel, p=parallel)

But Below script (from manual) cat not give me upspin/dnspin current of AP/P sates.
=================================================
transmission_spectrum = TransmissionSpectrum(
        configuration=device_configuration,
        energies=numpy.linspace(-0.5,0.5,10)*eV,
        kpoints=MonkhorstPackGrid(30,30)
        )
current = transmission_spectrum.current()
up_current = transmission_spectrum.current(spin=Spin.Up)
dn_current = transmission_spectrum.current(spin=Spin.Down)
==================================================

How to do to get upspin/dnspin current of AP/P, respectively?
Do I have to input Initial spin term?

I would be extremely grateful for your reply.
Best regards,

6

General Questions and Answers / Re: How to get Resistance-Area(RA) of MRAM by using ATK

« on: July 29, 2011, 10:47 »

Wow!
Very quick answer.

Thanx!!! 

7

Scripts, Tutorials and Applications / Re: Import/visualize VASP geometries in VNL 2010.02

« on: July 29, 2011, 10:41 »

It does not work.
May be, becase of ATK version difference (11.2)
woo....

8

General Questions and Answers / How to get Resistance-Area(RA) of MRAM by using ATK

« on: July 29, 2011, 10:15 »

Dear all,

In toturial document "First principles modelling of Electron transport across interfaces",
there are two main paramener of MRAM - TMR and RA.
It is easy to calculate TMR by using script of toturial.

Is there simple method or script to get RA?



I would be extremely grateful for your reply.
Best regards,

9

General Questions and Answers / Problem for ploting bandstructure or transmission

« on: June 29, 2011, 07:01 »

I sm testing QW to check performance by flowing tutorial about MTJ.

 :-[problem 1.
For continous calculation (ex) MTJ relaxation calculation -> MTJ parallel spin calculation)
When I select mgo_relax.nc and drag and drop it onto the "builder icon"
It's not working with flowing error massage

==========================================
Traceback (most recent call last):
  File "./zipdir/NL/GUI/MainWindow/MainWindow.py", line 433, in toolBarDropEvent
  File "./zipdir/NL/GUI/Tools/Builder/Builder.py", line 448, in dropReceiver
  File "./zipdir/NL/GUI/DragAndDrop/DropReceiver.py", line 70, in handleDrop
  File "./zipdir/NL/GUI/Tools/Builder/Builder.py", line 474, in plotObjectDrop
UnboundLocalError: local variable 'configuration' referenced before assignment


 :-[problem 2.
I cant plot any picture, band structure, transmission spetctrum, etc...
select band structure and click Show button then just blank plot pop up.

 (problem 3. (may be same problem with problem 2?)
And the tranmission analyzing script (which script came from tutorial of "Spin tranport in Magneto Tunnel Juctions")...
is not working with folloing error message.

====================================
Traceback (most recent call last):
  File "/tmp/2231961542871158.py", line 24, in <module>
    import pylab
  File "./build/atkpython/lib/python2.6/site-packages/pylab.py", line 1, in <module>
  File "./build/atkpython/lib/python2.6/site-packages/matplotlib/__init__.py", line 135, in <module>
  File "./build/atkpython/lib/python2.6/site-packages/matplotlib/rcsetup.py", line 19, in <module>
  File "./build/atkpython/lib/python2.6/site-packages/matplotlib/colors.py", line 54, in <module>
  File "./build/atkpython/lib/python2.6/site-packages/matplotlib/cbook.py", line 30, in <module>
  File "./build/atkpython/lib/python2.6/locale.py", line 530, in getpreferredencoding
  File "./build/atkpython/lib/python2.6/locale.py", line 494, in setlocale
locale.Error: unsupported locale setting
NanoLanguageScript execution failure


I'm looking forward for positive response.
Thanks.