Topics

1

General Questions and Answers / Band structure

« on: April 15, 2009, 07:28 »

Im intrested in finding band structure for graphenes and nanotubes.
My goal is to get these parametres
1)Fermi level
2)Band gap
3)Brillione zone direction
4)Is it metallic or semiconducting?

Should i choose "method" Brillouin Zone Integration?And can u explain what are these number of k points (A)(B) (C)?
In analysis tab when im intrested calculating energy bands,but i really dont understand what are below tab Band line points(scaled k-points)

About plotting graph.Along the x-axis i see only gamma to K or smth.But how does i know is "gamma" correspond to k=+-pii/a for example.When i resize plot,then there are nothing left in x-axis
I have no idea how to get band gap(Fermi level can be  calculated another analyses tab i presume)
Same problem for determining "metallic or semiconducting" state,because plot seems so crazy and im not sure making right consequences about their state

I looked at ATK tutorial(part 2,page 12) and saw some advanced graph.Is it possible to get the script?

2

General Questions and Answers / Bloch function

« on: March 16, 2009, 08:51 »

I remember somehow that,previous versons u had ability to show Bloch functions
I found internet such picture.How to get Bloch functions or similar picture in current version?

3

Future Releases / Open file feature?

« on: March 16, 2009, 04:14 »

I dont know how others are doing
But for example editor there should be "open file" feature
or even other virtual instruments.
Its so annoying to open file from results browser and copy to the other instruments.
It would be good if you can open several editors.

4

General Questions and Answers / Z-shaped nanoribbon junction

« on: March 16, 2009, 03:55 »

I tried to follow tutoriol,but i have some problems.
When i wanted to repace this part

import math, numpy
aCC = 1.4208
x_shift = -4.0*aCC*math.sqrt(3.)/2.
right_electrode_coordinates = (
numpy.array ( [[ 8.45349407, 7.5, 1.42086005],
...
[ 16.78999329, 7.5, 3.39222002]] )
+ array([x_shift,0.,0.]) ) * Angstrom

I got script

from ATK.TwoProbe import *

# Scattering elements and coordinates
scattering_elements = [Carbon,   Carbon,   Carbon,   Hydrogen,
                       Hydrogen, Carbon,   Carbon,   Carbon,   
                       Hydrogen, Hydrogen]
scattering_coordinates = [[  9.68399525,   7.5       ,   4.97301006],
                          [ 12.14499664,   7.5       ,   4.97301006],
                          [ 14.60599804,   7.5       ,   4.97301006],
                          [  7.5       ,   7.5       ,   5.13293982],
                          [ 16.78999329,   7.5       ,   5.13293982],
                          [  9.68399525,   7.5       ,  15.29286939],
                          [ 12.14499664,   7.5       ,  15.29286939],
                          [ 14.60599804,   7.5       ,  15.29286939],
                          [  7.5       ,   7.5       ,  15.1329394 ],
                          [ 16.78999329,   7.5       ,  15.1329394 ]]*Angstrom
       

electrode_elements = [Carbon,   Carbon,   Carbon,   Carbon,   
                      Carbon,   Carbon,   Carbon,   Carbon,   
                      Carbon,   Carbon,   Carbon,   Carbon,   
                      Carbon,   Carbon,   Hydrogen, Hydrogen,
                      Hydrogen, Hydrogen]
left_electrode_coordinates = [[  8.45349407,   7.5       ,   1.42086005],
                         [  8.45349407,   7.5       ,   2.8417201 ],
                         [  9.68399525,   7.5       ,   3.55215001],
                         [  9.68399525,   7.5       ,   0.71043003],
                         [ 10.91449547,   7.5       ,   1.42086005],
                         [ 10.91449547,   7.5       ,   2.8417201 ],
                         [ 12.14499664,   7.5       ,   3.55215001],
                         [ 12.14499664,   7.5       ,   0.71043003],
                         [ 13.37549782,   7.5       ,   1.42086005],
                         [ 13.37549782,   7.5       ,   2.8417201 ],
                         [ 14.60599804,   7.5       ,   3.55215001],
                         [ 14.60599804,   7.5       ,   0.71043003],
                         [ 15.83649921,   7.5       ,   1.42086005],
                         [ 15.83649921,   7.5       ,   2.8417201 ],
                         [  7.5       ,   7.5       ,   0.87036002],
                         [  7.5       ,   7.5       ,   3.39222002],
                         [ 16.78999329,   7.5       ,   0.87036002],
                         [ 16.78999329,   7.5       ,   3.39222002]]*Angstrom
import math, numpy
aCC = 1.4208
x_shift = -4.0*aCC*math.sqrt(3.)/2.
right_electrode_coordinates = (numpy.array (  [[  8.45349407,   7.5       ,   1.42086005],
                         [  8.45349407,   7.5       ,   2.8417201 ],
                         [  9.68399525,   7.5       ,   3.55215001],
                         [  9.68399525,   7.5       ,   0.71043003],
                         [ 10.91449547,   7.5       ,   1.42086005],
                         [ 10.91449547,   7.5       ,   2.8417201 ],
                         [ 12.14499664,   7.5       ,   3.55215001],
                         [ 12.14499664,   7.5       ,   0.71043003],
                         [ 13.37549782,   7.5       ,   1.42086005],
                         [ 13.37549782,   7.5       ,   2.8417201 ],
                         [ 14.60599804,   7.5       ,   3.55215001],
                         [ 14.60599804,   7.5       ,   0.71043003],
                         [ 15.83649921,   7.5       ,   1.42086005],
                         [ 15.83649921,   7.5       ,   2.8417201 ],
                         [  7.5       ,   7.5       ,   0.87036002],
                         [  7.5       ,   7.5       ,   3.39222002],
                         [ 16.78999329,   7.5       ,   0.87036002],
                         [ 16.78999329,   7.5       ,   3.39222002]] )+array([x_shift,0.,0.] ) )*Angstrom

electrode_cell = [[ 24.28999307,   0.        ,   0.        ],
                  [  0.        ,  24.28999307,   0.        ],
                  [  0.        ,   0.        ,   4.26258   ]]*Angstrom
# Set up electrodes
left_electrode_configuration = PeriodicAtomConfiguration(
    electrode_cell,
    electrode_elements,
    left_electrode_coordinates
    )
right_electrode_configuration = PeriodicAtomConfiguration(
electrode_cell,
electrode_elements,
right_electrode_coordinates
)
# Set up two-probe configuration
twoprobe_configuration = TwoProbeConfiguration(
    (left_electrode_configuration,right_electrode_configuration),
    scattering_elements,
    scattering_coordinates,
    electrode_repetitions=[[1,1],[1,1]],
    equivalent_atoms=([3,0],[2,5])
    )

I run that script Job manager

Running: C:\Program Files\QuantumWise\Virtual NanoLab 2008.10.0\atk\bin\atk.exe c:/docume~1/rain~1.rai/locals~1/temp/tmpvpio1e.nl
Traceback (most recent call last):
  File "c:/docume~1/rain~1.rai/locals~1/temp/tmpvpio1e.nl", line 89, in ?
    right_electrode_coordinates = (numpy.array (  [[  8.45349407,   7.5       ,   1.42086005],
NameError: name 'array' is not defined
Terminated Abnormally

5

General Questions and Answers / Nanotube Grower

« on: March 13, 2009, 17:45 »

I want to do some simple operation with nanotube
When i drag (4,4) Nanotube into nanolanguage script
I choosed,basis set and choosed from "Analyses" section all quantities
And im intrested in Eigenstates,Electron density,Eigenstates occupation and so on
I saved and dragged to the Job Manager.Everything seemed ok.
I wanted to see eigenstates,electron density in nanoscope,but when i dragged it to the
Nanoscope i saw empty space and when i selected Insert plot-Contour plot
i got some picture.      Is there sompthing wrong?Why there is no nanotube anymore?