Messages

91

Scripts, Tutorials and Applications / Re: Exporting electron density etc to XYZ file for plotting in other software

« on: December 28, 2008, 05:57 »

Dear Nordland,

Thank you again. The problem is that the script "export3d" was not attached to your first post I think 

This was also happenned to my another post once before, I think it is a problem with the forum's web coding 

If you could attach the script "export3d" again, I would be grateful 

Regards,

Serhan

92

General Questions and Answers / Re: How to find the dynamic capacitance of a nanowire in ATK?

« on: December 27, 2008, 20:44 »

Thank you very much! 

Regards

Serhan

93

Scripts, Tutorials and Applications / Re: Exporting electron density etc to XYZ file for plotting in other software

« on: December 27, 2008, 20:41 »

Dear Nordland,

Thank you very much for this script also . Unfortunately I could not get it work:

Code

from ATK.TwoProbe import *

# Enter the filename of the calculation.
filename = 'D:\Atomistix_works\Tut6\lih2li-scf.nc'
scf = restoreSelfConsistentCalculation(filename)
# Calculate the electron density.
electron_density = calculateElectronDensity(scf)
potential = calculateEffectivePotential(scf)
from export3d import *
export3D(electron_density)

gives:

Running: C:\Program Files\QuantumWise\Virtual NanoLab 2008.10.0\atk\bin\atk.exe c:/docume~1/atomis~1/locals~1/temp/tmpsqhecq.nl
Traceback (most recent call last):
  File "c:/docume~1/atomis~1/locals~1/temp/tmpsqhecq.nl", line 9, in ?
    from export3d import *
ImportError: No module named export3d
Terminated Abnormally

I'm using ATK 2008.10.0 in Windows.

Serhan

94

General Questions and Answers / Re: How to find the dynamic capacitance of a nanowire in ATK?

« on: December 27, 2008, 13:56 »

Hi Nordland,

Your answer and attached script is excellent, thank you very much! 

We can plot the simulation outputs for example electron density and potential profile in 3-D in VNL easily , Ok, it is very well. 

But, can we export these 3-D outputs to a simple file that can be read by any other math tool, for example to a xyz file such as: 

X coordinate        Y coordinate        Z coordinate       Electron density
1E-10                      1E-10                 1E-10               0.02
2E-10                      1E-10                 1E1-0               0.015
.                             .                         .                      .
.                             .                         .                      .

Thanks again...

Serhan 

95

General Questions and Answers / Re: how to choose the eigenchannel index

« on: December 26, 2008, 06:15 »

Hi anyipeng,

Quoting from the ATK manual from section "calculateTransmissionEigenstates":

"index is the transmission eigenvalue index (see calculateTransmissionEigenvalues
()). The transmission eigenvalue index may assume any integer value within the range
[0, Neigenchannels-1], where Neigenchannels indicates the number of eigenchannels which
corresponds to non-vanishing transmission eigenvalues."

So, to determine Neigenchannels, firstly you have to see the number of non-zero transmission eigenvalues.

Regards
Serhan

96

General Questions and Answers / How to find the dynamic capacitance of a nanowire in ATK?

« on: December 25, 2008, 21:37 »

Dear users,

Is it possible to calculate the dynamic capacitance of a nanowire or any other two-probe system in ATK?

I think, we can use C=Q/V formula.

* Can we extract Q(r) and V(r) (r being the 3-D posisiton vector, Q(r) being the 3-D charge matrix and V(r) is 3-D potential matrix of the scattering region) from the output file with extension .vnl  to another tool such as MATLAB? (I tried to read .nc file using a NetCDF reader but it was not straight )

If we can extract Q(r) and V(r) by simple element by element division I think a reasonable capacitance can be obtained. Also, it may be done with some NL coding  But extracting to MATLAB or sth else is also interesting I think.

Regards and nice Christmas and New Year

Serhan

97

Scripts, Tutorials and Applications / Re: Voltage sweep (I-V curve)

« on: December 16, 2008, 11:34 »

Thank you very much Dr. Blom. I will try as soon as possible:)

Regards
Serhan

98

Future Releases / Voltage sweep command would be useful

« on: December 9, 2008, 16:15 »

Hi all,

First of all, congratulations for the new company and the forum!

I would suggest that if there were a command that sweeps the bias voltage from an initial value to a final voltage with some steps, and if the current versus bias voltage was written down in the *.vnl file then to be plotted, would be useful in the following versions.

Regards,
Serhan