Nuclear moments in molecular spectroscopy

[Malamala]

Hello! I saw many paper extracting the magnetic dipole and electric quadrupole moments of the nuclei by performing RF/microwave spectroscopy on the rotational levels of a molecule. However, I can't seem to find paper measuring higher order moments. For example, the magnetic octupole moment has been measured in several atoms, so I expect it to be visible in a molecule containing the specific nucleus, too. I was wondering if anyone has seen such a paper and can point me towards it (I am more interested in the functional form the magnetic octupole moment operator in a molecule than in the experiment itself, so it can be also a theoretical paper). Thank you!

 

[Hyperfine]

A search of "magnetic octupole moment" on Google Scholar yields 15,900 hits.

 

[Malamala]

A search of "magnetic octupole moment" on Google Scholar yields 15,900 hits.

Yeah... how many of them are in a molecule...

 

[Hyperfine]

How much of your research work do you expect others to do for you?

 

[Twigg]

I would surprised if anyone's done this analysis, and if someone had, it still might not get published because there's little motivation for it. However, here's how I would start your literature search, if I were you:

The closest thing I know of that people actually study in molecules is the nuclear magnetic quadrupole moment. Because I'm an experimentalist, I only know the experimentalists who work on this, namely the Hutzler group at Caltech. Someone had to do the theory calculations for the energy shift due to MQM in a molecule. I would find out who did those calculations (it may be cited in one of the Hutzler group's papers), and look up their other works. If nothing else, the MQM calculations may give you insight on how the nuclear quadrupole calculation would look like.

Hope that helps.

 

[Malamala]

How much of your research work do you expect others to do for you?

Well if I couldn't find it online myself, asking here seems like a reasonable next step, no?

 

[Hyperfine]

Have you posed your question to your research mentor? If not, I urge you to do so.

Your mentor is, by far, the best source of assistance and guidance available to you with respect to your research activities.

 

[Malamala]

Have you posed your question to your research mentor? If not, I urge you to do so.

Your mentor is, by far, the best source of assistance and guidance available to you with respect to your research activities.

I did, I asked him and my colleagues... I don't understand how giving me these obvious pieces of advice like "ask your advisor" or "google magnetic octupole moment" is useful to me or others having the same question in future. These are things one obviously tries before asking it on a forum (and you know that very well). If you don't have an answer to my question you can either not answer at all (which is totally fine), or guide me in the right direction (like @Twigg did with his answer). But I really don't see what your replies are meant to achieve here.

 

[Hyperfine]

Forgive me for wasting your time with my antiquated academic philosophy. I assure you it will not happen again.

 

[Mark44]

Have you posed your question to your research mentor?

I did, I asked him and my colleagues... I don't understand how giving me these obvious pieces of advice like "ask your advisor" or "google magnetic octupole moment" is useful to me or others having the same question in future.

But you didn't include any of this information in your opening post, so how was @Hyperfine supposed to know this?

 

[Vanadium 50]

Also, you didnt say what the response was and how you found it unsatisfactory. That leaves @Hyperfine and others to guess.

 

[Malamala]

Also, you didn;t say what the response was and how you found it unsatisfactory. That leaves @Hyperfine and others to guess.

@Mark44 @Vanadium 50 really? Should I start my every post with "I googled .... and I didn't find the answer" and then post my actual question? Isn't it expected that one does this basics things before asking something here? Do I have to clearly state that I tried these things already? @Hyperfine I am sorry if you wrongly assumed because of me that I didn't bother to google "magnetic octupole moment", before asking it here (despite the fact that I asked many other molecular physics questions in the past and no one ever complained about me not googling the answer before).

@Vanadium 50 I am not sure what you mean by this "you didnt say what the response was and how you found it unsatisfactory". As I clearly stated, I couldn't find a paper giving a formula for the magnetic octupole moment in a molecule. What "response" do you mean?

 

[Mark44]

Should I start my every post with "I googled .... and I didn't find the answer" and then post my actual question?

No, you could start with the question, and then let people know what you have tried to do before coming here.

Isn't it expected that one does this basics things before asking something here?

It would be nice if this were so, but a significant number of people coming here don't do this.

 

[Malamala]

It would be nice if this were so, but a significant number of people coming here don't do this.

This might just be the case. But if someone actually did the bare minimum before posting the question here, telling him to google the answer won't help. If someone didn't do the bare minimum, they most probably knew they should have, so telling them that won't make them realize the mistake and actually do some search (they will most probably say they did and still wait for someone to give them the answer). My point is that literally everyone can think of googling the answer (whether they do it or not) so telling them to do it seems like it doesn't help in any way (neither to answer the question nor to make them be less lazy for the future).

I have enough experience in research to know at which point one should start asking for help, so I totally agree that googling and asking your lab mates are the first steps. I just don't think that someone reemphasizing the basics is useful (especially when my question involved a quite complex topic, not trying to quickly get the answer for my hw).

 

[Mark44]

But if someone actually did the bare minimum before posting the question here, telling him to google the answer won't help.

You seem to be missing the point. If someone did the bare minimum, but didn't tell us that they had done so, how would we know?

If someone didn't do the bare minimum, they most probably knew they should have, so telling them that won't make them realize the mistake and actually do some search

You would be surprised to find out how many people come here with no notion that they should do at least the bare minimum of groundwork before asking the question,

My point is that literally everyone can think of googling the answer

Too many think of this only after we make that suggestion.

 

[Hyperfine]

For the record, I was in no way making a complaint. Believe it or not I was attempting to be helpful. And no, I see no reason for a poster to anticipate what assumptions I, or any other reader of a thread, will or should make regarding a question or comment that is less than explicit and complete. Do I believe a student should run to the library rather than to an internet forum? Indeed I do. Do I believe the best source of assistance and guidance should come from the mentor and presumed principal investigator? Indeed I do. And I make no apologies for those beliefs.

I suspect that @Vanadium 50 was asking about the response of your mentor to your question. If so, I believe he has an excellent point.

Lastly, many people may well read a thread such as this. They should have the opportunity to benefit, if only in principle, from the discourse. An inexperienced student, possibly intimidated by the prospect of approaching his or her mentor when they encounter a problem just might reap such a benefit.

 

[Malamala]

For the record, I was in no way making a complaint. Believe it or not I was attempting to be helpful. And no, I see no reason for a poster to anticipate what assumptions I, or any other reader of a thread, will or should make regarding a question or comment that is less than explicit and complete. Do I believe a student should run to the library rather than to an internet forum? Indeed I do. Do I believe the best source of assistance and guidance should come from the mentor and presumed principal investigator? Indeed I do. And I make no apologies for those beliefs.

I suspect that @Vanadium 50 was asking about the response of your mentor to your question. If so, I believe he has an excellent point.

Lastly, many people may well read a thread such as this. They should have the opportunity to benefit, if only in principle, from the discourse. An inexperienced student, possibly intimidated by the prospect of approaching his or her mentor when they encounter a problem just might reap such a benefit.

I guess my confusion stems also from why this question? I posted a lot of questions here, never mentioned whether I googled it before or not (as I assumed it was obvious) and I always got helpful answers, without being told to google it before (or asked what did I do before asking the question here). Also many questions posted on this forum are asked directly, without the poster mentioning what steps they took before asking here. So why do I suddenly need to mention something that seemed obvious for all my other posts before?

In terms of being helpful, I still don't see how your comments to this thread helped me in any way (not trying to be sarcastic), while, as I mentioned before, @Twigg's answer actually took me in the right direction, without him needing a confirmation of whether I google the answer before.

 

[Malamala]

You would be surprised to find out how many people come here with no notion that they should do at least the bare minimum of groundwork before asking the question,

Too many think of this only after we make that suggestion.

Well I don't really know much about that, but even if it's true, it's probably true for when they ask the first 1-2 questions. Given that I asked few hundred questions (I assume my stats are publicly visible, right?), probably I know to google my question before coming here.

 

[Vanadium 50]

"My advisor told me to look it up in Guncotton and Farfoofnik*, but it only covers the dipole case, and I am interested in higher multipoles." Isn't that a better starting place?

Guessing is ineffectve amd appears to make you unhappy. So why make us do it?

* Not a real book.

 

[Malamala]

"My advisor told me to look it up in Guncotton and Farfoofnik*, but it only covers the dipole case, and I am interested in higher multipoles." Isn't that a better starting place?

Guessing is ineffectve amd appears to make you unhappy. So why make us do it?

* Not a real book.

In my case it was my advisor who asked me to look into this problem, but again I don't see how this piece of information can help others answer my question. As far as I can tell, am I expected to list all the places (books and websites?) I tried beforehand? That would mean that all the questions on this websites should start with a very long list of these initial attempts? What exactly do you mean by telling people what I tried so far? I tried quite a lot of things how many of them should I list?