Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - qweasel

Pages: [1] 2
1
General Questions and Answers / How to suppress intermediate output of CrystalStructurePrediction?
« on: April 30, 2017, 20:19 »
I'm using CrystalStructurePrediction inside a script. How can I suppress the intermediate output of this function? I'm not interested for the detailed progress to be printed on the screen. Also, I couldn't find documentation for that function and its output data structures.

2
General Questions and Answers / Re: Why I don't see LSDA under "Exchange correlation"?
« on: February 21, 2017, 13:13 »
Can you please briefly explain why spin polarization is needed here in the first place?

3
General Questions and Answers / Why I don't see LSDA under "Exchange correlation"?
« on: February 21, 2017, 02:38 »
I'm following your paper in PRB, where you used LSDA for Ni-graphene interface.

According to the NiO tutorial, LSDA is supposed to be listed under "Exchange correlation". However I only have LDA, GGA and MGGA there.

4
General Questions and Answers / How to build non-covalent graphene-metal interface?
« on: February 21, 2017, 01:48 »
In the tutorial "Graphene–Nickel interface", Ni is covalently bonded to graphene. In reality, it does not necessarily happen. What would be the correct way to attach/couple a non-covalent electrode to graphene?

5
General Questions and Answers / Re: What is the meaning of "current" in IV curves of periodic structures?
« on: February 20, 2017, 18:36 »
So if in the lateral directions I only have one unit cell, the current should be identical to current density?

6
General Questions and Answers / Re: What is the meaning of "current" in IV curves of periodic structures?
« on: February 17, 2017, 17:07 »
What I don't understand is why "current" is correct terminology if the device is infinite in both directions orthogonal to transport. How can you possibly calculate an integral quantity across an infinite cross section?

7
General Questions and Answers / MoS2 nanotube tutorial refers to dftb.org, but no MoS2 sets are available there
« on: February 17, 2017, 04:21 »
The MoS2 nanotube tutorial refers to [STT+00] and to dftb.org downloads, but no MoS2 parameter sets are availble.

What do I do?

8
General Questions and Answers / What is the meaning of "current" in IV curves of periodic structures?
« on: February 17, 2017, 03:13 »
What is the meaning of current in periodic structures that are infinite in A and B directions?
Why is it "current" and not "current density"?

9
General Questions and Answers / Geometry for transmission spectrum calculations: bulk or device?
« on: February 16, 2017, 17:56 »
In this tutorial a bulk configuration with the smallest unit cell is used for transmission spectrum, while in this tutorial a device configuration is used for transmission spectrum as well as other transport calculations. It also states:

Quote
electron transport calculation requires open boundary conditions in the transport direction

Is it correct to use bulk configuration to calculate transmission spectrum for more complex geometries?

10
General Questions and Answers / Which electrons are plotted in electron density plots?
« on: February 15, 2017, 01:50 »
When plotting results of "ElectronDensity" calculation, which electrons contribute to the calculated density?

11
General Questions and Answers / Re: Poisson solver settings for Electronic Transport Through A Distorted Nanoribbon
« on: February 14, 2017, 01:10 »
In the transport direction it is indeed Dirichlet. I was referring to the top/bottom direction. Why keep it as periodic in the case of a nanoribbon?

12
General Questions and Answers / Why default k_A, k_B, k_C values vary for bulk and for device?
« on: February 14, 2017, 01:03 »
When a simple bulk structure is sent to the script generator, the default values for k-point sampling density are kA=kB=kC=2, while for a device the default values are kA=kB=2, kC=400. Why the difference?

13
General Questions and Answers / Poisson solver settings for Electronic Transport Through A Distorted Nanoribbon
« on: February 13, 2017, 23:54 »
In the video "Electronic Transport Through A Distorted Nanoribbon", the settings of the Poisson solver are kept as default (FFT, periodic boundary conditions).

Why is that? If it's a ribbon, wouldn't more suitable boundary conditions be non-periodic?

14
General Questions and Answers / How to add multiple cut planes in the Viewer?
« on: February 10, 2017, 15:02 »
I would like to visualize calculation results (e.g. electron density) using 2 perpendicular cut planes. When I open the viewer I'm asked either isosurface or cut cut plane. Afterwards, under "Properties"->"Cut planes" I don't see any option to add a second cut plane. How can I achieve this?

15
General Questions and Answers / Re: What is the correct way to build an armchair-zigzag heterostructure device?
« on: February 10, 2017, 14:57 »
Attached.

Pages: [1] 2