Topics

1

General Questions and Answers / Forward and Reverse Biasing a Device

« on: June 4, 2013, 21:27 »

Hello
 I have to calculate  the i-v characteristics for positive bias (0 to 1 V) and I used the " for bias in numpy.linspace(0.,1,10)*Volt:" command
but in the analyzer panel its showing the i-v characteristics for negative bias (-1 to 0 V) why this is happening please explain..? 

2

General Questions and Answers / Electron Difference Density

« on: May 11, 2013, 09:29 »

Sir please tell me, what this Electron Difference Density evaluates..?
if it finds the probability of the presence of electron, then with the attached C-O molecule there has to be blue surface near gold side (electronegativity--2.54) and red surface near carbon(electronegativity--2.55) but it is giving something Iam not able to understand... so please explain.. 

3

General Questions and Answers / Taking avg from 3D grid

« on: March 19, 2013, 07:44 »

Sir please help me to understand, how you are obtaining avg. values from the Electrostatic Difference potential, through the code given in the mannual..
http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.electrostaticdifferencepotential.html 

4

General Questions and Answers / Electron and Hole Current

« on: March 4, 2013, 13:18 »

hello Everyone
I made a gold-ZigZag CNT-gold and calculated its IV characteristics, now I need to know the contribution of electrons and holes to that current.. so is there any way in ATK to get electron and hole current separately.. 

5

General Questions and Answers / Segmentation fault

« on: February 5, 2013, 11:49 »

hello
      I installed the ATK12.8 version but when Iam running any simulation its giving segmentation fault.. i attached the log file also ...

6

General Questions and Answers / Transmission spectrum

« on: November 1, 2012, 07:31 »

hello everyone
        can anyone provide me some paper related to transmission spectrum it will be very helpful for me to understand the I-V characteristics

7

General Questions and Answers / k-points

« on: November 1, 2012, 07:29 »

hello sir,
           can you please tell me the function of K-points that we take in calculator section and how to take it for any geometry because if i take a lower value it gives wrong results and increasing it it takes too much time to simulate

8

General Questions and Answers / OPTIMIZATION_PROBLEM

« on: October 30, 2012, 11:52 »

HELLO Everyone!!
              i have a nanotube structure which has a gas moleclue for adsorbtion, i put it for optimization with DFT (as its necessary to optimize before IV calculation) but the problem is its taking too much time 10-12 days . Is there anyway to reduce it??
Iam using sunfirecluster with 76 cores

9

General Questions and Answers / metal_nanotube

« on: October 27, 2012, 08:39 »

hello !!!!
          in order to calculate the IV characteristics for a metal_CNT(5nm)_metal using extended huckel, when i find the transmission spectrum b/w (-2,2)ev it shows negative  current for positive voltage.
          then to correct that i increased the range for the transmission spectrum from (-8,16)eV now its giving positive currents... so please tell me is it correct??

10

General Questions and Answers / SEGMENTATION FAULT

« on: October 25, 2012, 09:01 »

hiiii,
      i had installed 12.2 in replacement of 11.8 but on running the simulations it is giving the below error

11

General Questions and Answers / Aluminium_electrode

« on: October 17, 2012, 09:03 »

hello
     why electrode with aluminum is not been able to bond each other

12

General Questions and Answers / Bandstructure of "Metal-CNT-Metal" device

« on: October 10, 2012, 14:01 »

hello Everyone,
       Please help me in finding the band structure of the metal-cnt-metal device.

13

General Questions and Answers / Vacuum potential??

« on: July 27, 2012, 11:34 »

Hi,
   Can anyone let me know about the steps involved in calculating vacuum potential using ATK.

14

Scripts, Tutorials and Applications / Running from middle:

« on: July 17, 2012, 15:10 »

hi,
    I have attached two files here:
  1.Checkpoint.py (in this i can successfully save temporary .nc file in specified folder and at a given time)
  Problem with this script:
  a)as i have defined checkpoint file (ben.nc)for electrode calculation and (ben2.nc) for device calculation,however, the file is getting saved as ben2.nc only i.e for both electrode and device. Also,
ben2.nc is getting deleted after electrode calculation is finished and with the start of device calculation it is again saving temporary files as (ben2.nc). I want electrode calculated nc file and device calculated nc files separately. So that I can restart simulation from middle.

2.benzene_I_V2_resart.py( I want to restart it, using ben2.nc file, however, getting error as shown in third attachment.)
Problem:
 a)Can I restart from any point.

3. Screenshot.png(error file)
 
Plz correct the coding if possible.

15

Scripts, Tutorials and Applications / Reusing same electrodes:

« on: July 16, 2012, 14:02 »

Hi,
    I am doing the tutorial " Reuse the same electrode for many different calculations " (http://www.quantumwise.com/publications/tutorials/mini-tutorials) I have created succesully the (left_electrode.nc) and (right_electrode.nc), however when I am using (device.py) for simulation , it is not bypassing the electrode calculation. I am attaching the script , if anyone can correct the code.