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General Questions and Answers / Re: I-V curve at negative biases in 13.8
« on: September 9, 2014, 05:13 »
Has it been improved in the 2014.0 version?
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General Questions and Answers / k point
« on: September 5, 2014, 03:03 »
Hi,
What's the difference between the k points in New Calculator and Transmission Spectrum module?
Do they need to be setted as the same value?
My system is a metal-molecule-metal junction.
Thank you~~
What's the difference between the k points in New Calculator and Transmission Spectrum module?
Do they need to be setted as the same value?
My system is a metal-molecule-metal junction.
Thank you~~
3
General Questions and Answers / Can not open my project?
« on: August 21, 2014, 03:05 »
Hi,
I cannot open my project named 'wl-ttcb' from the path 'D:/wan/wl-ttcb'. This problem has appeared two times. Why does this happen?
My version is 13.8.0.
Thank you !
Linda
I cannot open my project named 'wl-ttcb' from the path 'D:/wan/wl-ttcb'. This problem has appeared two times. Why does this happen?
My version is 13.8.0.
Thank you !
Linda
4
General Questions and Answers / I-V curve at negative biases in 13.8
« on: August 12, 2014, 15:06 »
Hi，
I’m calculating the I-V curve of my metal-molecule-metal device using the I-V module in 13.8 version. In the Script window, there is three items: Device, New Calculator and IV curve. Positive and negative bias are calculated separately. For the positive case, I found that the SCF calculation is from 0 V to 2.0 V. However, for the negative case, I set the V1 as -2.0 V and found that the SCF calculation is from -2.0 V to 0 V.
Did I do anything wrong?
Thank you!
I’m calculating the I-V curve of my metal-molecule-metal device using the I-V module in 13.8 version. In the Script window, there is three items: Device, New Calculator and IV curve. Positive and negative bias are calculated separately. For the positive case, I found that the SCF calculation is from 0 V to 2.0 V. However, for the negative case, I set the V1 as -2.0 V and found that the SCF calculation is from -2.0 V to 0 V.
Did I do anything wrong?
Thank you!
5
General Questions and Answers / Re: Ralaxation of Au-molecule-Au junction
« on: July 16, 2014, 08:16 »
Thank you Zh!
Kind regards.
Kind regards.
6
General Questions and Answers / Re: Ralaxation of Au-molecule-Au junction
« on: July 16, 2014, 03:32 »1. Do you understand the concept (or physics meaning) of force and stress?
In the atomistic simulation, the terminology of 'force' usually means the force between atoms, while the "stress" is exerted on the cell. The former is correlated to the optimization of atomic positions and the latter for the length and shape of cell.
2. " I found some Au atoms in the surface layer depart from each other. Why did this happen?"
Why is it not possible to happen?!
It is better to make constraints on the atoms belonging to the electrode region and some of atoms in center region (at least those atoms just next to the electrode region)
Thanks a lot for your kind help!
1.I have learnt more about force and stress now according to your reply.
2.My molecular junction is consisted of electrode(3 layers),electrode extension(3 layers),surface(2 layers) and the molecule. You mean I'd better constrain the electrode and electrode extension layers, then relax the surface layers and molecule, am I right?
7
General Questions and Answers / Ralaxation of Au-molecule-Au junction
« on: July 15, 2014, 09:46 »
Hi，
I’m a newbie in ATK and get into trouble with the relaxation of the Au-molecule-Au junction.
(1) What’s the difference between maximum force and maximum stress? I think I don’t understand their physical meanings.
(2) I have built the molecular junction following Building a molecular junction: Au-DTB-Au. In the device optimization, I set the parameters:
maximum force=0.1, maximum stress=0.1, remove the tick from constraining the cell in the z-direction , and I didn’t constrain any atom.
However, in the relaxed device, I found some Au atoms in the surface layer depart from each other. Why did this happen? Is the optimization result reasonable and used in the next I-V calculation?
I’m a newbie in ATK and get into trouble with the relaxation of the Au-molecule-Au junction.
(1) What’s the difference between maximum force and maximum stress? I think I don’t understand their physical meanings.
(2) I have built the molecular junction following Building a molecular junction: Au-DTB-Au. In the device optimization, I set the parameters:
maximum force=0.1, maximum stress=0.1, remove the tick from constraining the cell in the z-direction , and I didn’t constrain any atom.
However, in the relaxed device, I found some Au atoms in the surface layer depart from each other. Why did this happen? Is the optimization result reasonable and used in the next I-V calculation?
8
General Questions and Answers / Re: layer number of Sceening region
« on: June 13, 2014, 02:42 »
What about the convergence experiment?Could you please tell me how to do it?
9
General Questions and Answers / layer number of Sceening region
« on: June 12, 2014, 04:36 »
Hi,
I'm new in ATK. Following the tutorial(http://quantumwise.com/publications/tutorials/builder/172-building-a-molecular-junction-au-dtb-au#userconsent#), I have learnt how to build a molecular junction.But recently, I was really confused by the layer number of Au atom in the screening region(including electrode extension and surface layers).I want to know:
1.What role do the extension and surface layer serve in the transmission calculation?
2.In the tutorial mentioned above, the screening region has four layers.If my mulecule (only having one benzene ring) is in the simialr size as BDT, will 4 layers in the screening region be OK?
3.Strictly speaking, "The required number of screening layers needs to be checked for convergence"(in tutorial http://quantumwise.com/documents/tutorials/latest/ATKTutorialDevice/index.html/chap.input.html). How to do the convergence experiment in ATK(please give as much detailed instruction as possible )
Thank you for your kind help!
I'm new in ATK. Following the tutorial(http://quantumwise.com/publications/tutorials/builder/172-building-a-molecular-junction-au-dtb-au#userconsent#), I have learnt how to build a molecular junction.But recently, I was really confused by the layer number of Au atom in the screening region(including electrode extension and surface layers).I want to know:
1.What role do the extension and surface layer serve in the transmission calculation?
2.In the tutorial mentioned above, the screening region has four layers.If my mulecule (only having one benzene ring) is in the simialr size as BDT, will 4 layers in the screening region be OK?
3.Strictly speaking, "The required number of screening layers needs to be checked for convergence"(in tutorial http://quantumwise.com/documents/tutorials/latest/ATKTutorialDevice/index.html/chap.input.html). How to do the convergence experiment in ATK(please give as much detailed instruction as possible )
Thank you for your kind help!
10
General Questions and Answers / Construction of a metal-molecule-metal junction
« on: June 10, 2014, 05:44 »
Hi,
I have built a molecule junction according to tutorial:
http://quantumwise.com/publications/tutorials/builder/172-building-a-molecular-junction-au-dtb-au#userconsent#
However, when I construct a device from bulk, I wanted to decrease the number of Au layer on the left to 3, equal to the case on the right, but failed.
Why the layer of electrode on the left can not be decreased to 3?
I have built a molecule junction according to tutorial:
http://quantumwise.com/publications/tutorials/builder/172-building-a-molecular-junction-au-dtb-au#userconsent#
However, when I construct a device from bulk, I wanted to decrease the number of Au layer on the left to 3, equal to the case on the right, but failed.
Why the layer of electrode on the left can not be decreased to 3?
11
General Questions and Answers / A Au-H bond?
« on: March 21, 2014, 13:34 »
Hi,
I am new here in ATK.When I put my molecule close to the surface of gold electrode, the hydrogen atom on a benzene ring connect to a gold one. I want to ask:
(1)Why does this happen?
(2)Will it make an effect on my calculation of transmission properties?
(3)If this is not correct, how do I clear the Au-H bond?
My version is 13.8.0.
Thank you !
I am new here in ATK.When I put my molecule close to the surface of gold electrode, the hydrogen atom on a benzene ring connect to a gold one. I want to ask:
(1)Why does this happen?
(2)Will it make an effect on my calculation of transmission properties?
(3)If this is not correct, how do I clear the Au-H bond?
My version is 13.8.0.
Thank you !
12
General Questions and Answers / Optimizing the molecular junction
« on: November 18, 2013, 05:53 »
Hi,
I have successfully constructed a molecular junction following the tutorial 'Building a molecular junction: Au-DTB-Au' step by step and the junction is similar to the picture.Before the calculations,how can I optimize the junction?
The more detail,the better because I major on experiments and know little about calculation.My version is 13.8.
Thank you !
Linda Wang
I have successfully constructed a molecular junction following the tutorial 'Building a molecular junction: Au-DTB-Au' step by step and the junction is similar to the picture.Before the calculations,how can I optimize the junction?
The more detail,the better because I major on experiments and know little about calculation.My version is 13.8.
Thank you !
Linda Wang
13
General Questions and Answers / Re: Regarding molecular junction geometry
« on: November 18, 2013, 01:55 »
Hi,
I'm new in ATK as well and I'm trying to learn how to build a molecular junction. There's a video about the "Building a molecular junction: Au-DTB-Au",which tell you
tep by step.Share it with you and hope it can help you to some extent
Website:
http://quantumwise.com/publications/tutorials/builder/172-building-a-molecular-junction-au-dtb-au
Linda Wang
I'm new in ATK as well and I'm trying to learn how to build a molecular junction. There's a video about the "Building a molecular junction: Au-DTB-Au",which tell you
tep by step.Share it with you and hope it can help you to some extent
Website:
http://quantumwise.com/publications/tutorials/builder/172-building-a-molecular-junction-au-dtb-au
Linda Wang
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