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General Questions and Answers / Re: Molecular Energy Spectrum
« on: March 29, 2015, 14:52 »
Would anyone please answer this? I badly need someone's help on this. Thanks in advance.
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General Questions and Answers / Re: Molecular Energy Spectrum
« on: March 27, 2015, 14:59 »
Hi, Umberto Martinez for replying. I don't think I have wholly got answers to my questions from previous post. I have 3 questions specifically:
(1) What do first and second column represent? Little elaboration will go a long way in helping me and others.
(2) As opposed to what you mentioned in your last post, the third column also contains some numbers like 9.999985e-01,8.939647e-02,1.532619e-04 and so on. Should I treat them as zero or what?
(3) Can you exactly point out HOMO and LUMO for spin-up and spin-down electrons from the result(mpsh0.nc) I attached in my last post? This would do a world of good to me.
Hoping to hear from you soon. Have a great day..!!
(1) What do first and second column represent? Little elaboration will go a long way in helping me and others.
(2) As opposed to what you mentioned in your last post, the third column also contains some numbers like 9.999985e-01,8.939647e-02,1.532619e-04 and so on. Should I treat them as zero or what?
(3) Can you exactly point out HOMO and LUMO for spin-up and spin-down electrons from the result(mpsh0.nc) I attached in my last post? This would do a world of good to me.
Hoping to hear from you soon. Have a great day..!!
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General Questions and Answers / Molecular Energy Spectrum
« on: March 27, 2015, 08:43 »
Hi,Everyone
Hope you are grand. I have obtained MolecularEnergySpectrum at 0 bias voltage for a MTJ in Parallel Configuration(PC) and the results(and py file) are attached here. I actually intend to calculate HOMO and LUMO energy-level at 0 bias for spin-up and spin-down carriers for this MTJ in PC but I can't seem to understand the results I have got(I hope this is the right way to find HOMO and LUMO). I seek your advice on how to find HOMO and LUMO for spin-up and spin-down carriers from these results and also what do the 3 columns under spin-up(and spin-down) represent. I hope I have provided enough information about my problem and am waiting for someone to address these issues. Have a nice day..!!
Hope you are grand. I have obtained MolecularEnergySpectrum at 0 bias voltage for a MTJ in Parallel Configuration(PC) and the results(and py file) are attached here. I actually intend to calculate HOMO and LUMO energy-level at 0 bias for spin-up and spin-down carriers for this MTJ in PC but I can't seem to understand the results I have got(I hope this is the right way to find HOMO and LUMO). I seek your advice on how to find HOMO and LUMO for spin-up and spin-down carriers from these results and also what do the 3 columns under spin-up(and spin-down) represent. I hope I have provided enough information about my problem and am waiting for someone to address these issues. Have a nice day..!!
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General Questions and Answers / Re: Change in HOMO-LUMO gap with change in Voltage
« on: March 26, 2015, 20:29 »
Sir, I would really appreciate if you could provide an answer to previous question(s) promptly. I am actually kind of stuck at it and I gotta move on. So just waiting for your expert comments. You have a great day..!!
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General Questions and Answers / Re: Change in HOMO-LUMO gap with change in Voltage
« on: March 25, 2015, 14:11 »
I am not sure if I fully understand what you mean by the first question in your last post. 
But I am guessing you mean an .nc file(s) like "ivcurve_selfconsistent_configurations.nc", which I do have and I got it by calculating I-V curve for the MTJ in PC(and later in APC). In order to find HOMO and LUMO, I think I need to calculate Molecular Energy Spectrum for spin up and spin down electrons in PC as well as APC at different bias voltages for the MTJ. So I would be grateful if you could explain in a bit detail as to how to go about this calculation with aforementioned nc file(s) at my disposal. Waiting for your replay at the earliest. You have a nice day..!! 
But I am guessing you mean an .nc file(s) like "ivcurve_selfconsistent_configurations.nc", which I do have and I got it by calculating I-V curve for the MTJ in PC(and later in APC). In order to find HOMO and LUMO, I think I need to calculate Molecular Energy Spectrum for spin up and spin down electrons in PC as well as APC at different bias voltages for the MTJ. So I would be grateful if you could explain in a bit detail as to how to go about this calculation with aforementioned nc file(s) at my disposal. Waiting for your replay at the earliest. You have a nice day..!!
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General Questions and Answers / Change in HOMO-LUMO gap with change in Voltage
« on: March 25, 2015, 06:44 »
Hi, Everyone
I would be grateful if you could help me resolve an issue i am having. I earlier calculated I-V characteristic of a two probe geometry(specifically a MTJ) through Analysis -> I-V curve method for PC and APC. Now I want to find the HOMO-LUMO gap at different bias voltages. Please tell me how i can find this change in HOMO-LUMO gap with the change in bias voltages from above I-V curve result at the earliest. I look forward to your comments. Have a blessed day..!!
I would be grateful if you could help me resolve an issue i am having. I earlier calculated I-V characteristic of a two probe geometry(specifically a MTJ) through Analysis -> I-V curve method for PC and APC. Now I want to find the HOMO-LUMO gap at different bias voltages. Please tell me how i can find this change in HOMO-LUMO gap with the change in bias voltages from above I-V curve result at the earliest. I look forward to your comments. Have a blessed day..!!
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General Questions and Answers / ATK compatability
« on: February 23, 2015, 11:34 »
Hello,
Everyone
I have one geometry in ATK 2008 with me. However, i also like to use the same geometry in ATK 2014. Is there any way to use the geometry made in ATK 2008 in ATK 2014? If yes then please guide me as to how to go about it? Have a nice day..!!
Everyone
I have one geometry in ATK 2008 with me. However, i also like to use the same geometry in ATK 2014. Is there any way to use the geometry made in ATK 2008 in ATK 2014? If yes then please guide me as to how to go about it? Have a nice day..!!
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General Questions and Answers / Negative TMR
« on: February 11, 2015, 08:12 »
Hi,
I intend to calculate TMR at diff. bias voltages for a MTJ. Now i read in one paper the TMR equation which is (Ipc-Iapc)/Iapc. Unfortunately in my case Iapc is greater than Ipc at all bias voltages (Am i wrong right here?) and hence according to the aforementioned TMR eq. i get negative TMR. So i was wondering if it was justifiable to have negative TMR or i should really tinker the equation a little like (Iapc-Ipc)/Ipc. I am waiting for a comment on this..!!
I intend to calculate TMR at diff. bias voltages for a MTJ. Now i read in one paper the TMR equation which is (Ipc-Iapc)/Iapc. Unfortunately in my case Iapc is greater than Ipc at all bias voltages (Am i wrong right here?
) and hence according to the aforementioned TMR eq. i get negative TMR. So i was wondering if it was justifiable to have negative TMR or i should really tinker the equation a little like (Iapc-Ipc)/Ipc. I am waiting for a comment on this..!!
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General Questions and Answers / Resuming calculation
« on: December 11, 2014, 11:57 »
Hi, I wanted to calculate I-V characteristic at diff. biases (0,0.1,0.2,....,1.2 V) for a two-terminal device. I was running this simulation on cluster and it,due to some reason, got killed when it was in the middle of the convergence process at the last bias point(1.2 V). Now I have been through one tutorial on this and other posts(most of which pertain to old versions) on this forum and frankly speaking i am a noob in Quantumwise so pardon me if it comes across as very basic stuff. In my log file, it shows Checkpoint file location in tmp folder but when i tried to locate it, i couldn't find it. For the record, it has been 15 days since the job got killed on cluster. So could someone please explain the whole resuming process in a little detail?
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General Questions and Answers / Re: Transmission Spectrum
« on: November 28, 2014, 09:50 »
Let me see if i get this right. You are basically saying that it doesn't matter as far as time consumption is concerned whether we calculate IV curve or just transmission spectra at different biases. Is that what you mean? And yeah, Thanks again for your time.
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General Questions and Answers / Re: nA and nB sampling points' values
« on: November 28, 2014, 07:14 »
I am not sure if i understand completely... 
Yeah, but thanks all the same.
Yeah, but thanks all the same.
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General Questions and Answers / Re: Transmission Spectrum
« on: November 28, 2014, 07:13 »
Thanks for your reply. Yeah, i know how to carry out IV curve analysis at different biases and there by clicking on Add more plots i can see dI/dV and transmission spectra. But what i actually meant was that if i could just calculate transmission spectra at different biases without being forced to carry out computationally intensive and time consuming IV curve analysis? i just want to see the transmission spectra at different biases without spending much time. Hope this makes sense.
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General Questions and Answers / Re: nA and nB sampling points' values
« on: November 26, 2014, 18:17 »
Thanks for the reply. And one more thing. In fe-mgo-fe tutorial, in calculator nA=6,nB=6,nC=100 and in transmission spectrum nA=30,nB=30. Is there any relation between these two pair of (nA,nB)? Is it possible for them to be completely different from each-other?
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General Questions and Answers / Transmission Spectrum
« on: November 26, 2014, 12:32 »
Hi
i want to calculate transmission spectrum at different biases for a two terminal device in one go. is it possible and if yes then how?
i want to calculate transmission spectrum at different biases for a two terminal device in one go. is it possible and if yes then how?
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General Questions and Answers / nA and nB sampling points' values
« on: November 26, 2014, 10:08 »
Hi,
I intend to calculate transmission spectrum and IV curve for a FM-semiconductor-FM structure. I am not sure what values should i assign to nA and nB sampling points in the transmission spectrum analysis box. I have gone through similar Fe/Mgo/Fe tutorial and there they have kept nA=nB=1 and i think it is because it's not a 3D structure while my structure is 3D and that's why nA=nB=1 might not be appropriate for a 3D structure. I reckon in my case nA and nB should be 3 since it's a 3D structure. I will appreciate an expert remark on this. Have a nice day..!!
I intend to calculate transmission spectrum and IV curve for a FM-semiconductor-FM structure. I am not sure what values should i assign to nA and nB sampling points in the transmission spectrum analysis box. I have gone through similar Fe/Mgo/Fe tutorial and there they have kept nA=nB=1 and i think it is because it's not a 3D structure while my structure is 3D and that's why nA=nB=1 might not be appropriate for a 3D structure. I reckon in my case nA and nB should be 3 since it's a 3D structure. I will appreciate an expert remark on this. Have a nice day..!!
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