Messages

1

General Questions and Answers / calculation for PDOS

« on: August 11, 2009, 10:15 »

I wish to calculate Density of States projected on s- orbitals for a two probe system. how to do it?

2

Scripts, Tutorials and Applications / Re: how to view electron density with isosurface option

« on: August 5, 2009, 12:29 »

this is the log for my scf calculation.


# sc 236 : q =  692.96685 e  Etot = -12616.42988 Ry  dRho =  9.8658E-03  dEtot = -2.2788E-05 Ry


 after this i run a separate script for electron density calculation. that log show q = 692.96685 e. then how can you say system converged to zero charge?

3

Scripts, Tutorials and Applications / Re: how to view electron density with isosurface option

« on: August 5, 2009, 10:52 »

i used contour plot for electron density calculation. it shows the election density around the atoms but why doesn't it get reflected in isosurface plot?

4

Scripts, Tutorials and Applications / how to view electron density with isosurface option

« on: August 5, 2009, 08:57 »

i am calculating the electron density of gold two probe system . when i drag this vnl file to Nanoscope I couldn't able to view the electron density with isosurface option. i have exported that picture for your attention.

5

Scripts, Tutorials and Applications / How to do I- V measurements

« on: July 31, 2009, 06:12 »

i have finished 0V studies on a gold two probe system. Now i would like to apply some potential and calculate transmission spectrum,current, etc. For example if i wish to do 1V is it necessary to run a scf and then to do current and transmission calculations?

Thanks in advance.

6

Scripts, Tutorials and Applications / Re: transmission spectrum

« on: July 30, 2009, 11:06 »

ya it works well. how can i able to get these data into a text file for future reference?

Thanks in advance

7

Scripts, Tutorials and Applications / Re: transmission spectrum

« on: July 30, 2009, 10:57 »

i got this following output in command line after adding that line

Please enter VNL file name: Au100-Au8-Au100_Transmission_4*4*100.vnl
The following samples are present in this VNL file:
['Au100-Au8-Au100']
Please enter sample name to extract (default=first sample):
['Transmission Spectrum T(E)']
---------------------------------------------------------------------------
exceptions.KeyError                                  Traceback (most recent call last)

/home/rocks2/valsa/prem/kpoints/extract_transmission_from_vnl_file.py
     32
     33 # Some older versions used "Transmission Spectrum" or "TransmissionSpectrum"
---> 34 trans = data['Transmission Spectrum Transmission Spectrum']
     35 print 'Energy (eV)\tTotal transmission'
     36 print '----------------------------------'

KeyError: 'Transmission Spectrum Transmission Spectrum'
WARNING: Failure executing file: <extract_transmission_from_vnl_file.py>
ATK 2008.10.0 Linux-x86_64 build 14677 2008-11-27

8

Scripts, Tutorials and Applications / Re: transmission spectrum

« on: July 30, 2009, 10:45 »

when i execute that file i got this following error in command prompt. since the vnl file contains only one sample i hit enter, when it asked me to enter sample name.

Please enter VNL file name: Au100-Au8-Au100_Transmission_4*4*100.vnl
The following samples are present in this VNL file:
['Au100-Au8-Au100']
Please enter sample name to extract (default=first sample):
---------------------------------------------------------------------------
exceptions.KeyError                                  Traceback (most recent call last)

/home/rocks2/valsa/prem/kpoints/extract_transmission_from_vnl_file.py
     30
     31 # Some older versions used "Transmission Spectrum" or "TransmissionSpectrum"
---> 32 trans = data['Transmission Spectrum Transmission Spectrum']
     33 print 'Energy (eV)\tTotal transmission'
     34 print '----------------------------------'

KeyError: 'Transmission Spectrum Transmission Spectrum'
WARNING: Failure executing file: <extract_transmission_from_vnl_file.py>
ATK 2008.10.0 Linux-x86_64 build 14677 2008-11-27

9

Scripts, Tutorials and Applications / Re: transmission spectrum

« on: July 30, 2009, 09:44 »

when i right clicked in the Result browser it shows option for "export plot". then there are 3 options to save that spectrum. ( .ps, .eps, .png) but all are exporting the plot. So tell me how to import the data into a text file.

10

Scripts, Tutorials and Applications / transmission spectrum

« on: July 30, 2009, 05:47 »

i am calculating the transmission spectrum for gold atoms. whenever i opened vnl file through result browser, i see transmission spectrum in which transmission is in horizontal axis and energy in  vertical axis. i wish to exchange that co ordinates. i.e to plot transmission in vertical axis and energy in horizontal axis. how to do it?

11

Scripts, Tutorials and Applications / calculting DOS and LDOS

« on: July 28, 2009, 07:40 »

i finished scf calculations for two probe system. now i wish to calculate some physical properities lik DOS, LDOS. Can i use restore check point file option to do it faster? or i have to start it from beginning?. i have attached the script which i used for scf calculation.

12

Scripts, Tutorials and Applications / transmission spectrum

« on: July 28, 2009, 06:49 »

i am studying transmission spectrum for gold two probe system. in first step i did the scf calculations. and after that i used the attached script to plot the transmission spectrum . i got the vnl file too. The problem is when opened that vnl file in result browser, i cant apply to see the full figure. the transmission scale only shows from 0 to 1. how to adjust the scale to see whole transmission spectrum say 0 to 3 in transmission scale.

And if i wish to exchange the co-ordinates, i.e energy in x-axis and transmission in y-axis how to do it?

thanks in advance

13

Scripts, Tutorials and Applications / restore scf calculations

« on: July 24, 2009, 06:55 »

Hello,

I am calculating the transport properties of gold two probe system.  I mentioned 300 iterations for convergence in the script. when i run this script i got the error "exceeded the maximum number of self-consistent iterations". so I need to increase the iteration steps. But i wish to continue from last iteration(i.e from 300 iteration). I don't know how to do it with netCDF file. I have attached the script and log for your attention.

14

Scripts, Tutorials and Applications / Re: creation of netCDF files

« on: July 8, 2009, 06:10 »

is that log shows the convergence??

15

Scripts, Tutorials and Applications / creation of netCDF files

« on: July 7, 2009, 10:10 »

i used the following script to configure a two probe system. but i couldn't see the creation of netCDF file. i have attached the log for your attention. i can't see the convergence.