Topics

121

General Questions and Answers / ATK-SE Slater Koster, DFTB: transmission property.....

« on: November 29, 2013, 18:38 »

Sir,
May be these questions are repetitive...But, I really need to know the answers.....
 
1) Whether the semi empirical Slater-Koster model (with DFTB,CP2K basis set) can be (rather, should be) used to find out the transmission property of any defected (where the periodicity has been perturbed ) carbon based system ??    Is the default one is "Pi" model..??
2) If yes, then.... can the max. interaction range be varied....to any higher value from the default 10 angstrom....so that it can provide more accurate results??
Besides, I wanted to know that....

3) If I have to look at the fact that, how a perturbation hampers the overall transmission in case of any electrical transport (from one port to the other)........ then, where should I set the energy value pointer...??  Should I set it to the point...for which I'm getting the max. transmission??

122

General Questions and Answers / Spatial Regions: Inclusion of an Oxide Layer

« on: November 12, 2013, 17:57 »

Sir
If I have to see the effect of changing the Oxide layer in case of any device.... then simply changing it, using the "spatial regions" interface, will do the job(reflecting the effect of the alternation in the transmission)?? / or, I need to make an interfacing between the oxide and the transport layer material....?? 

123

General Questions and Answers / computed multigrid residual is greater than the required accuracy

« on: November 8, 2013, 15:08 »

WARNING                                                             
# The computed multigrid residual is greater than the required accuracy.     
# Computed residual :   1.20533e-11                                         
# Required accuracy :   1.00000e-12                                           

............ What does this warning message signify???                                 

124

Scripts, Tutorials and Applications / IndentationError/Electrode properties

« on: October 5, 2013, 22:24 »

Sir
While running a simple script, to find out the plot of Cond. V/s. Temp. ....I'm getting the following error...
May I know, what is the cause of this error...

___________________________
Script:

#calculate the conductance for each temperature in the temperature list
for i in range(len(temperature_list)):
conductance_list=transmission_spectrum.conductance(
electrode_temperatures=(temperature_list,temperature_list) )
#plot the conductance as function of temperature
import pylab
pylab.figure()
pylab.semilogy(temperature_list,conductance_list)
pylab.xlabel("Temperature (K)")
pylab.ylabel("Conductance (S)")
pylab.show()
______________________________________

Error:
------------------------------------------------------------------------------+
| NanoLanguageScript execution started                                         |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|                                                                              |
| Atomistix ToolKit 12.8.2 [Build c2e18ea]                                     |
|                                                                              |
+------------------------------------------------------------------------------+
  File "/tmp/6998650439471636.py", line 11
    conductance_list=transmission_spectrum.conductance(
                   ^
IndentationError: expected an indented block
+------------------------------------------------------------------------------+
| NanoLanguageScript execution finished                                        |
+------------------------------------------------------------------------------+

125

Installation and License Questions / problem in running vnl @ ATK 13.8.b1

« on: September 21, 2013, 13:37 »

Hi
As I'm trying to install ATK 13.8.b1 in RHEL-6.1 (or, even in 6.3)... It's getting Installed with out any issue... But while I'm trying to run the vnl (after setting the proper path at .bashrc).... I'm facing the problem as denoted bellow.
___________________
Traceback (most recent call last):
  File "./zipdir/NL/GUI/Main/SplashScreen.py", line 94, in run
  File "./zipdir/NL/GUI/MainWindow/MainWindow.py", line 13, in <module>
  File "./zipdir/NL/GUI/Actions/ToolFactory.py", line 8, in <module>
  File "./zipdir/NL/GUI/Tools/OldViewer/OldViewer.py", line 20, in <module>
  File "./zipdir/NL/GUI/Graphics/GL/GLPlotManager.py", line 28, in <module>
  File "./zipdir/NL/GUI/Graphics/GL/GLContourBox.py", line 5, in <module>
  File "./zipdir/NL/GUI/Graphics/GL/GLContour.py", line 20, in <module>
  File "./build/vnl/lib/python2.7/ctypes/__init__.py", line 431, in LoadLibrary
  File "./build/vnl/lib/python2.7/ctypes/__init__.py", line 353, in __init__
OSError: libGL.so: cannot open shared object file: No such file or directory
_______________________________________________________________________

 NB:- On the other hand....instead of ATK 13.8.b1 ..., if I go for installing ATK 12.8...., it is working absolutely fine...  

CAN anybody tell me the reason behind this.....,  and how to get 13.8.b1 installed, properly.....

126

General Questions and Answers / Phonon Dispersion

« on: August 26, 2013, 20:55 »

Can anybody help me to find out the phonon dispersion, for any 2D material (e.g., graphene), using vnl 13.8.b1