46
General Questions and Answers / Re: spin-dependent Seeback coefficients
« on: May 27, 2015, 12:52 »
Here is the script
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47
General Questions and Answers / Re: spin-dependent Seeback coefficients
« on: May 27, 2015, 03:46 »
Hi, Jess, thank you very much for your reply.
As a further estimation, I calculated a spin polarized model according to the tutorial (i.e. http://www.quantumwise.com/publications/tutorials/item/112-transmission-spectrum-of-a-spin-polarized-atomic-chain)
For the parallel case, the spin-polarized spetra were well re-produced.
However, when I caculated the spin-seeback coefficients and total seeback coefficients of the system at 300K, the results are:
*************
spin=1 : Seebeck coefficient=-1.530e-06 V/K
spin=2 : Seebeck coefficient=1.236e-03 V/K
*************
Peltier Coefficient -0.0004587 V
Seebeck Coefficient -1.529e-06 V/K
Thermal Conductance (electrons) 8.206e-10 W/K
Thermal Conductance (phonons) - W/K
Thermal Conductance (total) - W/K
ZT -
*************
I have two questions:
Q1. It seems that S2 is larger than S1 by about three orders of magnitude (absolute values). however, the total S is only closed to S1. According to your above reply, I think S=(S1+S2)/2=S2 rather than S1. Is the result right?
Q2. This question is another independent question.
I further caculated the spin-polarized transsimisson spetra of the sytems at finite bias (Vb=0.2 V) . How to get the spin-polarized current? Through the Tool-Custom Analyzer-IVcurve, it seems that only total current can be obtained, although the transsimisson spetra are spin polarized .
**********The results from IV Curve Plugin*****************
+----------------------------------------------------------+
| Current Report |
+----------------------------------------------------------+
| Applied bias = -0.200 Volt |
| Bias window = [0.000 Volt, 0.200 Volt] |
| Bias window covered = 100.00 % |
| Calculated current = -1.51330794906e-05 A |
| Spin = Sum |
+----------------------------------------------------------+
Data for interpolation
Voltage list (Volt)
[-0.2]
Current list (nano Ampere)
[-15133.07949056]
**********************************************
In addition, the nc files are large (20-30 MB), so I can not upload them. But the script is uploded. See next!
Thank you in advance!
As a further estimation, I calculated a spin polarized model according to the tutorial (i.e. http://www.quantumwise.com/publications/tutorials/item/112-transmission-spectrum-of-a-spin-polarized-atomic-chain)
For the parallel case, the spin-polarized spetra were well re-produced.
However, when I caculated the spin-seeback coefficients and total seeback coefficients of the system at 300K, the results are:
*************
spin=1 : Seebeck coefficient=-1.530e-06 V/K
spin=2 : Seebeck coefficient=1.236e-03 V/K
*************
Peltier Coefficient -0.0004587 V
Seebeck Coefficient -1.529e-06 V/K
Thermal Conductance (electrons) 8.206e-10 W/K
Thermal Conductance (phonons) - W/K
Thermal Conductance (total) - W/K
ZT -
*************
I have two questions:
Q1. It seems that S2 is larger than S1 by about three orders of magnitude (absolute values). however, the total S is only closed to S1. According to your above reply, I think S=(S1+S2)/2=S2 rather than S1. Is the result right?
Q2. This question is another independent question.
I further caculated the spin-polarized transsimisson spetra of the sytems at finite bias (Vb=0.2 V) . How to get the spin-polarized current? Through the Tool-Custom Analyzer-IVcurve, it seems that only total current can be obtained, although the transsimisson spetra are spin polarized .
**********The results from IV Curve Plugin*****************
+----------------------------------------------------------+
| Current Report |
+----------------------------------------------------------+
| Applied bias = -0.200 Volt |
| Bias window = [0.000 Volt, 0.200 Volt] |
| Bias window covered = 100.00 % |
| Calculated current = -1.51330794906e-05 A |
| Spin = Sum |
+----------------------------------------------------------+
Data for interpolation
Voltage list (Volt)
[-0.2]
Current list (nano Ampere)
[-15133.07949056]
**********************************************
In addition, the nc files are large (20-30 MB), so I can not upload them. But the script is uploded. See next!
Thank you in advance!
48
General Questions and Answers / Re: spin-dependent Seeback coefficients
« on: May 26, 2015, 01:54 »
Thank you for your help, Jess. 
As an example, I performed a spin-polarized calculations on a carbon nanoribbons with LSDA (the obtained transsmission spetra are therefore symmetric about spin-up and -down components, and the spin seebeck coefficent (SSC) should be the same for both spins).
I tested the 'seebeck.py' file that you provide, and found two questions:
Q1. Indeed, the spin-up and spin-down SSC are the same. I also calculated the total seebeck coefficent through 'thermalelectric coefficent', however, I found that the three values, spin-up, spin-down and the total, are the same. i.e. S1=S2=S. I think S should be equal to S1+S2?
Q2. If I want to get the relationship about S1~T, S2~T (T is the absolute temperature), what shall I do? (I understand that the default temperature is the electron temperature of two electrodes, for example, both are 300 K. How to get S1 and S2 under other temperatures?)
Thank you in advance!
As an example, I performed a spin-polarized calculations on a carbon nanoribbons with LSDA (the obtained transsmission spetra are therefore symmetric about spin-up and -down components, and the spin seebeck coefficent (SSC) should be the same for both spins).
I tested the 'seebeck.py' file that you provide, and found two questions:
Q1. Indeed, the spin-up and spin-down SSC are the same. I also calculated the total seebeck coefficent through 'thermalelectric coefficent', however, I found that the three values, spin-up, spin-down and the total, are the same. i.e. S1=S2=S. I think S should be equal to S1+S2?
Q2. If I want to get the relationship about S1~T, S2~T (T is the absolute temperature), what shall I do? (I understand that the default temperature is the electron temperature of two electrodes, for example, both are 300 K. How to get S1 and S2 under other temperatures?)
Thank you in advance!
49
General Questions and Answers / Re: spin-dependent Seeback coefficients
« on: May 25, 2015, 15:55 »The attached script shows how one should be able to calculate the Seebeck coefficient for each spin channel. You'll need an nc-file containing the electronic TransmissionSpectrum. The script has been only moderately tested, but I think it should work.
Thank you for your help, Jess.
I will test it. If I have questions, I will contact you.
50
General Questions and Answers / Re: spin-dependent Seeback coefficients
« on: May 25, 2015, 03:48 »I assumed you were already familiar with our tutorial on computing the thermoelectric coefficients?Yes. However, what i want to know is the "spin-dependent" Seeback coefficients.
http://quantumwise.com/documents/tutorials/latest/Phonon/index.html/chap.thermoelectric.html
How can i seperate the spin-up and -down transmission spetra in one file in VNL? So we can calculate the spin-dependent coeffients seperately. are there some plugins?
Thank you!
51
General Questions and Answers / Re: spin-dependent Seeback coefficients
« on: May 24, 2015, 14:09 »... in the plugin.
But you can of course always evaluate it yourself from the spin-dependent transmission spectrum.
Thank you for your reply, Blom.
However, can you please say it more clearly? Where can i get and install the plugin. It seems that the plugin is not in the "Addon manager".
Thank you in advance.
52
General Questions and Answers / Re: The error of Phonon transmission spectrum
« on: May 20, 2015, 14:12 »
Thank you for your reply.
53
General Questions and Answers / spin-dependent Seeback coefficients
« on: May 20, 2015, 14:01 »
Hi all,
If I perform a spin-polarized calculation for a magnetic device, can I get the spin-dependent Seeback coefficients? It seems that ATK can only give the total Seeback coefficients through the 'Thermoelectronic Coefficients' plugin in VNL.
Thank you in advance.
If I perform a spin-polarized calculation for a magnetic device, can I get the spin-dependent Seeback coefficients? It seems that ATK can only give the total Seeback coefficients through the 'Thermoelectronic Coefficients' plugin in VNL.
Thank you in advance.
54
General Questions and Answers / Re: The error of Phonon transmission spectrum
« on: May 13, 2015, 15:41 »
Thank you. I will wait for the answer.
55
General Questions and Answers / The error of Phonon transmission spectrum
« on: May 11, 2015, 16:35 »
Hi, everyone,
Recently, I intend to calculate a phonon transmission spectrum of a device using SE method (see the .py file). However, there is a mistake during the calculation (see the e1657 file). I think I need help.
Thank you in advance.
Recently, I intend to calculate a phonon transmission spectrum of a device using SE method (see the .py file). However, there is a mistake during the calculation (see the e1657 file). I think I need help.
Thank you in advance.
56
General Questions and Answers / The Error
« on: April 12, 2015, 17:23 »
Hi,
When I do a NEB calculation, the log file indicates that there is a mistake "Attempting to use an MPI routine before initializing MPICH". However, for other calculations, such as band structure calculation, the ATK runs OK (Please note that there only one CPU in the computer, it has 4 cores).
My OS is 64-Win7. Please tell me why.
Thank you!
When I do a NEB calculation, the log file indicates that there is a mistake "Attempting to use an MPI routine before initializing MPICH". However, for other calculations, such as band structure calculation, the ATK runs OK (Please note that there only one CPU in the computer, it has 4 cores).
My OS is 64-Win7. Please tell me why.
Thank you!
57
General Questions and Answers / The error about VNL
« on: March 31, 2015, 02:00 »
Hi everyone
I have a question about VNL. For my computer, I can open VNL before. However, yesterday I wanted to build a new project through VNL, but the VNL 'die' .
Then I have to close the VNL, and try to open it again but failed. I found that, if I double click the icon, after 'checking liense' and 'initializing', the VNL can NOT open. But the process 'vnl.exe' will appear in the Task manager.
THANK YOU1
I have a question about VNL. For my computer, I can open VNL before. However, yesterday I wanted to build a new project through VNL, but the VNL 'die' .
Then I have to close the VNL, and try to open it again but failed. I found that, if I double click the icon, after 'checking liense' and 'initializing', the VNL can NOT open. But the process 'vnl.exe' will appear in the Task manager.
THANK YOU1
58
General Questions and Answers / Re: Can ATK simulate the relation between temperature and transport property(I-V)?
« on: March 25, 2015, 17:06 »
Thank you for your idea.
However, each configuration probably has different weigh factor [For example, Boltzmann distribution, exp(-E/kT) ]. How to consider the distribution in the "average value" of the transport properties? and is it meaningful?
However, each configuration probably has different weigh factor [For example, Boltzmann distribution, exp(-E/kT) ]. How to consider the distribution in the "average value" of the transport properties? and is it meaningful?
59
General Questions and Answers / Initial spin state for non-collinear calculations
« on: March 25, 2015, 16:53 »
Hi Everyone
Now I have two questions.
1. It is well known that, in a non-collinear spin calculation, the initial magnetic moment on an atom should be a vector with x, y and z components. However, in the "initial state\user spin", only one spin number can be modified rather than three. I wonder how to give a initial spin for an atom with three required components. For example, I want to give a fixed spin state for an atom, and the relative values of the three components are x=0.5, y=0.5, z= -1.
2. Can ATK give the orbital magnetic moment when the spin-orbital interaction is considered?
Thank you!
Now I have two questions.
1. It is well known that, in a non-collinear spin calculation, the initial magnetic moment on an atom should be a vector with x, y and z components. However, in the "initial state\user spin", only one spin number can be modified rather than three. I wonder how to give a initial spin for an atom with three required components. For example, I want to give a fixed spin state for an atom, and the relative values of the three components are x=0.5, y=0.5, z= -1.
2. Can ATK give the orbital magnetic moment when the spin-orbital interaction is considered?
Thank you!