Requesting guidance in understanding results from Athena

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EXAFS fitting sum of all paths in...

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Postdoctoral fellowship in AI -...

Deepak Varanasi

13 Sep 2020 13 Sep '20

5:45 p.m.

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Anatoly Frenkel

13 Sep 13 Sep

5:55 p.m.

Where is the conundrum? You make rbkg smaller and you see more low frequency features in EXAFS, as expected. Anatoly On Sun, Sep 13, 2020 at 1:47 PM Deepak Varanasi wrote:

...

Good afternoon

I hope that you are doing well and are healthy. My name is Deepak

Varanasi and ii am an undergraduate student at Middle Tennessee State University In need of your guidance for my thesis project. I am having trouble interpreting results for my EXAFS analysis done on Athena – specifically, the emergence of a signal in R-space, below the 1 – angstrom mark, after suppressing it via its rbkg parameter (signified by the black arrows). I have checked my back ground reduction and normalization multiple time sand have failed to isolate the reason behind my results or maybe it is the due to the gaps in my knowledge that prohibit my understanding of the results. At the risk of sounding armature, may I request your guidance in resolving my conundrum please? I would be honored to have your council in solving, understanding and comprehending the physical and chemical implications of my results. For your convenience, I have also appended a picture of my results to illustrate my query. Kindly contact me at your earliest convenience and please stay safe and healthy.

Yours Sincerely

Deepak Varanasi

P.S.: For your convenience, I have also appended a picture of my results to illustrate my query.

Resulting R – space graphs: -

[image: An Ink Drawing With Ink Annotations]

Resulting R – space graphs: -

[image: An Ink Drawing]

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

Carlo Segre

9:33 p.m.

New subject: [Ext] Re: Requesting guidance in understanding results from Athena

There is no physical meaning. It is simply a bad numerical background subtraction. Carlo On Sun, Sep 13, 2020 at 4:18 PM Deepak Varanasi wrote:

...

Good afternoon

The problem lies with understanding the meaning behind signals occurring below the 1-angstrom mark. The location of the peaks and the physical meaning thereof are making no sense to me. Kindly provide me with your guidance in facilitating my understanding.

Yours Sincerely

Deepak Varanasi

Sent from Mail https://go.microsoft.com/fwlink/?LinkId=550986 for Windows 10

*From: *Anatoly Frenkel *Sent: *Sunday, September 13, 2020 12:58 *To: *XAFS Analysis using Ifeffit *Subject: *Re: [Ifeffit] Requesting guidance in understanding results from Athena

Where is the conundrum? You make rbkg smaller and you see more low frequency features in EXAFS, as expected.

Anatoly

On Sun, Sep 13, 2020 at 1:47 PM Deepak Varanasi wrote:

Good afternoon

I hope that you are doing well and are healthy. My name is Deepak

Varanasi and ii am an undergraduate student at Middle Tennessee State University In need of your guidance for my thesis project. I am having trouble interpreting results for my EXAFS analysis done on Athena – specifically, the emergence of a signal in R-space, below the 1 – angstrom mark, after suppressing it via its rbkg parameter (signified by the black arrows). I have checked my back ground reduction and normalization multiple time sand have failed to isolate the reason behind my results or maybe it is the due to the gaps in my knowledge that prohibit my understanding of the results. At the risk of sounding armature, may I request your guidance in resolving my conundrum please? I would be honored to have your council in solving, understanding and comprehending the physical and chemical implications of my results. For your convenience, I have also appended a picture of my results to illustrate my query. Kindly contact me at your earliest convenience and please stay safe and healthy.

Yours Sincerely

Deepak Varanasi

P.S.: For your convenience, I have also appended a picture of my results to illustrate my query.

Resulting R – space graphs: -

[image: An Ink Drawing With Ink Annotations]

Resulting R – space graphs: -

[image: An Ink Drawing]

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

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-- Carlo U. Segre -- Duchossois Leadership Professor of Physics Director, Center for Synchrotron Radiation Research and Instrumentation Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre@iit.edu http://phys.iit.edu/~segre segre@debian.org

Mike Massey

9:36 p.m.

It sounds to me like you are understanding things well. The short, short version is that the purpose of the rbkg parameter is to filter out the low-frequency oscillations (arising from any of numerous sources) in the spectrum, that correspond to interatomic distances that make no physical sense. Or maybe I don't get it either ;) Scott Calvin's book has a nice discussion of these points, I recommend it. Kind Regards, Mike

...

On Sep 14, 2020, at 9:18 AM, Deepak Varanasi wrote:

Good afternoon

The problem lies with understanding the meaning behind signals occurring below the 1-angstrom mark. The location of the peaks and the physical meaning thereof are making no sense to me. Kindly provide me with your guidance in facilitating my understanding.

Yours Sincerely Deepak Varanasi

Sent from Mail for Windows 10

From: Anatoly Frenkel Sent: Sunday, September 13, 2020 12:58 To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Requesting guidance in understanding results from Athena

Where is the conundrum? You make rbkg smaller and you see more low frequency features in EXAFS, as expected. Anatoly

On Sun, Sep 13, 2020 at 1:47 PM Deepak Varanasi wrote: Good afternoon

I hope that you are doing well and are healthy. My name is Deepak Varanasi and ii am an undergraduate student at Middle Tennessee State University In need of your guidance for my thesis project. I am having trouble interpreting results for my EXAFS analysis done on Athena – specifically, the emergence of a signal in R-space, below the 1 – angstrom mark, after suppressing it via its rbkg parameter (signified by the black arrows). I have checked my back ground reduction and normalization multiple time sand have failed to isolate the reason behind my results or maybe it is the due to the gaps in my knowledge that prohibit my understanding of the results. At the risk of sounding armature, may I request your guidance in resolving my conundrum please? I would be honored to have your council in solving, understanding and comprehending the physical and chemical implications of my results. For your convenience, I have also appended a picture of my results to illustrate my query. Kindly contact me at your earliest convenience and please stay safe and healthy.

Yours Sincerely Deepak Varanasi

P.S.: For your convenience, I have also appended a picture of my results to illustrate my query.

<57BA12E4C0E6403EA1E7F05BCB60610D.png>

Resulting R – space graphs: -

<13111BEC5BCF46A8A8E5CDAE32782D44.png>

<4A7FE6C9D4EC4E0F83E8B43E23D5ED48.png>

Resulting R – space graphs: -

<83E495E5D37B431AB31567B6ED982716.png>

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

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Deepak Varanasi

9:39 p.m.

Good afternoon That makes sense. Thank you. I am glad and honored to have seeked all your guidance. Thank you, everyone. Yours sincerely Deepak Varanasi On Sun, Sep 13, 2020, 16:37 Mike Massey wrote:

...

It sounds to me like you are understanding things well. The short, short version is that the purpose of the rbkg parameter is to filter out the low-frequency oscillations (arising from any of numerous sources) in the spectrum, that correspond to interatomic distances that make no physical sense.

Or maybe I don't get it either ;)

Scott Calvin's book has a nice discussion of these points, I recommend it.

Kind Regards,

Mike

On Sep 14, 2020, at 9:18 AM, Deepak Varanasi wrote:

Good afternoon

The problem lies with understanding the meaning behind signals occurring below the 1-angstrom mark. The location of the peaks and the physical meaning thereof are making no sense to me. Kindly provide me with your guidance in facilitating my understanding.

Yours Sincerely

Deepak Varanasi

Sent from Mail https://go.microsoft.com/fwlink/?LinkId=550986 for Windows 10

*From: *Anatoly Frenkel *Sent: *Sunday, September 13, 2020 12:58 *To: *XAFS Analysis using Ifeffit *Subject: *Re: [Ifeffit] Requesting guidance in understanding results from Athena

Where is the conundrum? You make rbkg smaller and you see more low frequency features in EXAFS, as expected.

Anatoly

On Sun, Sep 13, 2020 at 1:47 PM Deepak Varanasi wrote:

Good afternoon

I hope that you are doing well and are healthy. My name is Deepak

Varanasi and ii am an undergraduate student at Middle Tennessee State University In need of your guidance for my thesis project. I am having trouble interpreting results for my EXAFS analysis done on Athena – specifically, the emergence of a signal in R-space, below the 1 – angstrom mark, after suppressing it via its rbkg parameter (signified by the black arrows). I have checked my back ground reduction and normalization multiple time sand have failed to isolate the reason behind my results or maybe it is the due to the gaps in my knowledge that prohibit my understanding of the results. At the risk of sounding armature, may I request your guidance in resolving my conundrum please? I would be honored to have your council in solving, understanding and comprehending the physical and chemical implications of my results. For your convenience, I have also appended a picture of my results to illustrate my query. Kindly contact me at your earliest convenience and please stay safe and healthy.

Yours Sincerely

Deepak Varanasi

P.S.: For your convenience, I have also appended a picture of my results to illustrate my query.

<57BA12E4C0E6403EA1E7F05BCB60610D.png>

Resulting R – space graphs: -

<13111BEC5BCF46A8A8E5CDAE32782D44.png>

<4A7FE6C9D4EC4E0F83E8B43E23D5ED48.png>

Resulting R – space graphs: -

<83E495E5D37B431AB31567B6ED982716.png>

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

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Deepak Varanasi

9:39 p.m.

Good afternoon I understand. In that case, would it be possible for you to perhaps guess the greatest factor causing this problem? My apologies if I may be asking for too much. Yours sincerely Deepak Varanasi On Sun, Sep 13, 2020, 16:39 Deepak Varanasi wrote:

...

Good afternoon

That makes sense. Thank you. I am glad and honored to have seeked all your guidance. Thank you, everyone.

Yours sincerely Deepak Varanasi

On Sun, Sep 13, 2020, 16:37 Mike Massey wrote:

...
It sounds to me like you are understanding things well. The short, short version is that the purpose of the rbkg parameter is to filter out the low-frequency oscillations (arising from any of numerous sources) in the spectrum, that correspond to interatomic distances that make no physical sense.

Or maybe I don't get it either ;)

Scott Calvin's book has a nice discussion of these points, I recommend it.

Kind Regards,

Mike

On Sep 14, 2020, at 9:18 AM, Deepak Varanasi wrote:

Good afternoon

The problem lies with understanding the meaning behind signals occurring below the 1-angstrom mark. The location of the peaks and the physical meaning thereof are making no sense to me. Kindly provide me with your guidance in facilitating my understanding.

Yours Sincerely

Deepak Varanasi

Sent from Mail https://go.microsoft.com/fwlink/?LinkId=550986 for Windows 10

*From: *Anatoly Frenkel *Sent: *Sunday, September 13, 2020 12:58 *To: *XAFS Analysis using Ifeffit *Subject: *Re: [Ifeffit] Requesting guidance in understanding results from Athena

Where is the conundrum? You make rbkg smaller and you see more low frequency features in EXAFS, as expected.

Anatoly

On Sun, Sep 13, 2020 at 1:47 PM Deepak Varanasi wrote:

Good afternoon

I hope that you are doing well and are healthy. My name is Deepak

Varanasi and ii am an undergraduate student at Middle Tennessee State University In need of your guidance for my thesis project. I am having trouble interpreting results for my EXAFS analysis done on Athena – specifically, the emergence of a signal in R-space, below the 1 – angstrom mark, after suppressing it via its rbkg parameter (signified by the black arrows). I have checked my back ground reduction and normalization multiple time sand have failed to isolate the reason behind my results or maybe it is the due to the gaps in my knowledge that prohibit my understanding of the results. At the risk of sounding armature, may I request your guidance in resolving my conundrum please? I would be honored to have your council in solving, understanding and comprehending the physical and chemical implications of my results. For your convenience, I have also appended a picture of my results to illustrate my query. Kindly contact me at your earliest convenience and please stay safe and healthy.

Yours Sincerely

Deepak Varanasi

P.S.: For your convenience, I have also appended a picture of my results to illustrate my query.

<57BA12E4C0E6403EA1E7F05BCB60610D.png>

Resulting R – space graphs: -

<13111BEC5BCF46A8A8E5CDAE32782D44.png>

<4A7FE6C9D4EC4E0F83E8B43E23D5ED48.png>

Resulting R – space graphs: -

<83E495E5D37B431AB31567B6ED982716.png>

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

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Ravel, Bruce

6:46 p.m.

You should read this: https://bruceravel.github.io/demeter/documents/Athena/bkg/rbkg.html B On 9/13/20 1:45 PM, Deepak Varanasi wrote:

...

Good afternoon

I hope that you are doing well and are healthy. My name is Deepak

Varanasi and ii am an undergraduate student at Middle Tennessee State University In need of your guidance for my thesis project. I am having trouble interpreting results for my EXAFS analysis done on Athena – specifically, the emergence of a signal in R-space, below the 1 – angstrom mark, after suppressing it via its rbkg parameter (signified by the black arrows). I have checked my back ground reduction and normalization multiple time sand have failed to isolate the reason behind my results or maybe it is the due to the gaps in my knowledge that prohibit my understanding of the results. At the risk of sounding armature, may I request your guidance in resolving my conundrum please? I would be honored to have your council in solving, understanding and comprehending the physical and chemical implications of my results. For your convenience, I have also appended a picture of my results to illustrate my query. Kindly contact me at your earliest convenience and please stay safe and healthy.

Yours Sincerely

Deepak Varanasi

P.S.: For your convenience, I have also appended a picture of my results to illustrate my query.

Resulting R – space graphs: -

An Ink Drawing With Ink Annotations

Resulting R – space graphs: -

An Ink Drawing

_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit

-- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS-II Lead Beamline Scientist, 6BM (BMM) Building 743, Room 114 Upton NY, 11973 Homepage: http://bruceravel.github.io/home/ Beamline: https://www.bnl.gov/ps/beamlines/beamline.php?r=6-BM Software: https://github.com/bruceravel Demeter: http://bruceravel.github.io/demeter/

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Anatoly Frenkel
Carlo Segre
Deepak Varanasi
Mike Massey
Ravel, Bruce

Requesting guidance in understanding results from Athena

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