Messages

1

General Questions and Answers / Re: Tellurium MGGA.TB09LDA basis set

« on: May 26, 2015, 09:31 »

Hi,
the default basis set for Te is indeed faulty. As a temporary solution, use the OpenMX pseudopotential and basis set. Both can be set up in the Script Generator in VNL. Get back to us if you experience any problems or if more questions arise.

Thanks again for your notification

2

Future Releases / Re: Integrate a desk calculator into vnl

« on: December 2, 2014, 09:34 »

yep, that's what i meant.of course, more functions would be nice...

3

Future Releases / Add sympy to atkpython

« on: December 2, 2014, 09:19 »

Sympy is a python module that allows for symbolic math in a fashion similar to mathematica. I use it a lot in development but also in atk sessions. 

4

Future Releases / Integrate a desk calculator into vnl

« on: October 24, 2014, 11:50 »

Hi,
I often find myself in situations where I need to make a quick numeric calculation, e.g. sqrt, exp, divisions, summation of whatever quantities. Here, a little calculator app would be handy that sits in the sidebar
and can be launched directly from within vnl.

5

General Questions and Answers / Re: Optical spectrum-bug???

« on: August 25, 2014, 09:27 »

the plots though show the dielectric constant.

6

General Questions and Answers / Re: single electron transistor: global name 'numpy' is not defined

« on: August 22, 2014, 13:12 »

  File "C:\Program Files (x86)\QuantumWise\atk-11.2.2\atkpython\lib\site-packages\readTotalEnergy.py", line 1
    Import numpy

Write "import" instead of "Import" (lower case i).

On the other hand, that line should not be necessary if you have the "from NanoLanguage import *" in your script as Ander suggested.

7

General Questions and Answers / Re: Can not open my project?

« on: August 21, 2014, 08:30 »

hi linda.
can you please check if the file project.ini exists in your project directory. also please check that you have read and write permissions on all files in the directory.

if all this is ok, then please provide a few more details: do you get an error message? if yes, what does it say? what is the exact behaviour you observe?

thanks for your patience,

carsten

8

General Questions and Answers / Re: Optical spectrum-bug???

« on: August 20, 2014, 15:15 »

The values reported by nlprint() and nlsave() are the SUSCEPTIBILITIES. Sorry for the confusion.

9

General Questions and Answers / Re: Graphyne device

« on: August 7, 2014, 08:36 »

hi maneesh,
i looked at your structure, and it looks ok. in particular, both electrodes have the same length. they might still be too short though.

then, i reproduced your steps, took the central region and clicked Device from Bulk. I manually set both electrodes to 7.0 A.
what you see at the bottom of the window are not the electrode sizes but steps in which you can increase/decrease the central region size, i.e. here you can shift the electrode-central region
boundary. the fact that these steps are different from left to right electrode indicate that the code has difficulties in actually finding good matches based on the periodicity in the z direction.
this is also the reason why you do not see any predefined electrode lengths in the electrode length combo box.

10

General Questions and Answers / Re: Total dipole moment

« on: August 6, 2014, 10:54 »

if you have the dipole moment vector as [dx, dy, dz], than
take the norm as d_total = (d[0]**2 + d[1]**2 + d[2]**2)**0.5

hope that's what you meant.

11

General Questions and Answers / Re: MoS2 Bandstructure

« on: July 18, 2013, 16:34 »

hi,
to your first question:

I'm not particularly sure about the k-point sampling, kindly take a look and direct me

the k-sampling is indeed odd. you probably want a k-grid of (nkx, nky, nkz) = (5, 1, 5) as opposed to (5, 5, 1) as in your script.

apply the following change in mos2structure.py:

Code

numerical_accuracy_parameters = NumericalAccuracyParameters(
    k_point_sampling=(5, 1, 5),
    )

or use the gui.

With that change applied, i can run it in roughly 20 minutes on a single core.

hope that helps you to get started.

best regards, carsten