Messages

46

General Questions and Answers / Export data format

« on: January 11, 2017, 15:37 »

Export of transmission data is giving out put in the following format

...
 -2.000000e+00   6.999983e+00
 -1.980000e+00   6.999996e+00
 -1.960000e+00   6.999998e+00
...

while I need the data in this format (below)
...
2.0106192983e+12   1.9142005976e+00
2.0734511514e+12   1.9023768591e+00
2.1362830044e+12   2.2092658409e+00
...

How to get this?

47

Future Releases / Re: Hope the hybrid functional can be implemented

« on: January 6, 2017, 20:12 »

Pls introduce HSE06 soon.

48

General Questions and Answers / Re: Peltier coefficient

« on: January 6, 2017, 12:31 »

Thanks

49

General Questions and Answers / Re: Device supercell heterojunction

« on: January 6, 2017, 09:28 »

Okay thank you.

50

General Questions and Answers / Re: Device supercell heterojunction

« on: January 5, 2017, 16:13 »

No in fact I want a (A)-(B) system i.e. both sides semi-infinite. So just making A-B in bulk and then make device from bulk should do the trick ?

I mean (A)-A-B-(B) ?

51

General Questions and Answers / Device supercell heterojunction

« on: January 4, 2017, 23:01 »

If we have a heterojunction device supercell (i.e. two different materials A aand B junction at the middle of the central "Device region") as in http://quantumwise.com/support/tutorials/item/94-carbon-nanotube-junctions

and make  a device from Bulk config/ molecular config, what determines whether the electrodes will be considered as periodic? (i.e. is it necessary to have the length of the electrode region to be physically much longer than the central region or vice versa to assume ideal contacts)

Before making the device (i.e. the bulk config) if we repeat the structure in C it becomes A-B-A-B-A-B, what ensures that when we make a device configuration, that it is actually a A-B heterojunction we are simulating.

I just want to know how ATK handles this internally and makes the choice?

52

General Questions and Answers / Peltier coefficient

« on: January 4, 2017, 22:50 »

In the tutorial https://quantumwise.com/documents/tutorials/latest/Phonon/index.html/chap.thermoelectric.html

It's mentioned "For an undoped nanoribbon, the Fermi level is in the middle of the band gap. To get a significant Peltier coefficient, the Fermi level must be at a band edge, corresponding to a doped nanoribbon. The plugin allows for shifting the Fermi level, and Figure 7 shows the result for \Delta E_F = 0.08 eV, corresponding to an n-doped nanoribbon. "

What happens if it is a metallic nanoribbon? Do we still need doping for getting significant Peltier coeff. even though there are states at Ef=0 ?

53

General Questions and Answers / Re: ATK Classical

« on: December 21, 2016, 20:02 »

Okay maybe I was bit confused with it. Earlier versions didn't strike out calculations (analysis) that were not possible in the GUI, so that made me think it may be it was possible.

54

General Questions and Answers / ATK Classical

« on: December 21, 2016, 13:57 »

In the recent versions of QuantumWise it is not possible to do electronic bandstructure calculations with ATK Classical anymore. However in the earlier releases it was very much possible to do so. Why has the functionality been turned off and is there a workaround.
It can be accuracy issue I understand but say just for testing different classical potentials if I do need some results it is no longer possible to have them.
Is it possible to work around the GUI with scripting.

55

General Questions and Answers / Re: Export data Bandstructure -problem

« on: December 12, 2016, 10:54 »

Yes. In windows sometime there are errors in saving in formats other than .png , but could be problem on my system also.

56

General Questions and Answers / Re: Export data Bandstructure -problem

« on: December 10, 2016, 19:13 »

Maybe, but also a little more about selecting range would be good, like I want a specific range say +2 to -2 eV. Its better to enter with keyboard than try with the zoom tool.
You can add free form drag and move for controlling the legend position.
Option to turn fermi level and other markers on/ off.
Some annotation tools like textbox and arrows etc.
These things would be handy.
All the graphs are fine for viewing, the only problem happens when making them into camera ready graphics for publishers.
Also A very useful thing would be a "make default" option for these cutomizations. If someone needs a large no. of plots with same layout and quality.

57

General Questions and Answers / FHI-aims input file with VNL

« on: December 9, 2016, 17:45 »

How can we build input files for FHI-aims with VNL. I have FHI installed separately (not part of ATK package) on a different system. Is it possible to do something similar to the VASP scripter? I can make FHI input files with VNL then. Would be very helpful.

58

General Questions and Answers / Re: Export data Bandstructure -problem

« on: December 9, 2016, 17:42 »

Yes, features like changing font size of the axes (and adding formulas/ symbols in axes), width of ticks, control over number of ticks etc., exporting with desired resolution 600/300 dpi in differente formats like .eps / .tiff etc. That would be nice.

59

General Questions and Answers / Export data Bandstructure -problem

« on: December 6, 2016, 20:05 »

I want to export data in *.dat format and only need the two columns. I am always getting *.txt files and 4 columns. VNL 2015 used to work fine if I exported from the 2D plot bandstructure. The BS 2D plot is also missing in 2016. Please correct this so I can export 2 columns in .dat.
I tried renaming the files but then the columns are not properly recognized in plotting software as Origin.

60

General Questions and Answers / Re: total energy for hetro structure

« on: November 21, 2016, 21:31 »

Total energy / atom is a more realistic estimate maybe. To find global minima vary interlayer distance and calculate total energy/atom for each case, then just plot. You have to run an optimization loop for that purpose.