Talk:Morse/Long-range potential

Residual use of the Morse potential

It was stated by user: https://en.wikipedia.org/wiki/Special:Contributions/87.77.234.110 that the Morse potential might still be used for fits to spectroscopic data. However, a search on Google scholar: https://scholar.google.com/scholar?as_ylo=2011&q=morse+potential&hl=en&as_sdt=0,5 does not show any empirical potentials fitted to the Morse model since the MLR was introduced in 2009. Rosen-Morse and "Generalized Morse" are shown, but not plain Morse. Dr. Universe (talk) 11:57, 18 April 2015 (UTC)

Undefined terms

The functions presented in this article in the Function section do not have any of their terms defined. See: https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Mathematics for standards of presentation. Leperflesh (talk) 18:44, 5 November 2019 (UTC)

Good point, $r_{e}$ was defined but not ${\mathfrak {D}}_{e}$ (Depth of the potential at equilibrium). I'll look at the others too. Dr. Universe (talk) 21:27, 25 May 2021 (UTC)

Hope you've been well in the past two and a half years. I'm going to update the commentary on that equation to define ${\mathfrak {D}}_{e}$ as "depth of the potential at equilibrium", since it still is not defined. Ideally, there should be a veritable source that we can cite for that section with the definitions, but I'd rather make this first clarification as a stepping-stone. In fact, I found this comment in this talk page because I got confused by the lack of a definition and came here to complain about it. -- QB2k (talk) 13:12, 21 December 2023 (UTC)

2007 paper

@JoelleJay:,@TheLawGiverOfDFT::

• Eq 14 of the 2007 paper is incorrect if you work out the calculus as $r\rightarrow \infty$, and I can't even see how it could be consolidated or compatible with the description in this wiki article which follows the later articles (2009 and beyond).
• Eq. 12 is also incorrect, for a completely independent reason. It's missing the quadratic term from the Wikipedia article, which means the MLR which is supposed to be Morse-like when $r\approx \infty$ and have the correct long-range when $r\approx \infty$ (for example C6/r^6), unfortunately does not have the correct long-range as you will get C6 + [some other wrong stuff...].
• So the authors of this paper "thought" they had created a truly Morse/long-range potential, but due to miscalculations in Eq. 12 the long-range part was not correct.
• I cannot even see this 2007 paper on LeRoy's Google Scholar page, so it would appear that with the above errors LeRoy does not endorse the paper.
• Furthermore, the end of the 2007 paper expresses hopes that the MLR can become even more realistic (allowing more complicated u(r) functions, damping functions, more than two C coefficients, etc.).
• All of the above were fixed in the 2008 and 2009 papers: the 2008 one pointing out the problem and how to fix it, and the 2009 ones both implementing the more complicated u(r) incorporating 2-state coupling. The 2011 paper (Dattani & LeRoy, Journal of Molecular Spectroscopy) went as far as 3-state coupling and I've never seen anyone go beyond 3 states.
• Notice Eq. 11 of the 2007 paper is also not the same in the subsequent papers starting with the 2009 conference paper which you can download from the Ohio State University archive (I believe I gave the page number in the AfD discussion, but it might have put <-- --> around it because those discussions started getting very long!).
• There's more differences between the 2007 paper and the later ones, as there's no room for the q parameter and the y variable is centered around a fixed constant re rather than a variable r_reff.

So while it makes sense to have the 2007 paper cited in the article (indeed it was cited, just not in the opening part, I really wrote the article with the 2008 version of the MLR potential in mind, since that's what other authors such as Stolyarov, Tiemann, and the ab initio people use when they report results with the MLR. I didn't know about the 2008 paper at the time of writing the article (I was forced to dig that one up due to the AfD discussion with Joelle), so I cited the 2009 paper and named the two theorists, plus Coxon since he introduced a new variable (m) and called it the MLR3 in 2010, but now 8 years have passed since I wrote the Wiki article in 2013 and the MLR3 isn't really being used, so Coxon doesn't really need to be named. I've corresponded with Coxon many times and as recently as 2019, and in 2020 with one of his long-time co-authors. I did a lot of research before making this article.

TheLawGiverOfDFT: I see you wrote out your suspicions about who a user is "in real life" in the edit summary, and I just wanted to let you know that I've got in trouble for doing that before. Everything here is publicly available and permanent in the revision history, so we just have to be a bit careful about everything we write, especially allegations before having definitive proof. Also the public doesn't know who "TheLawGiverOfDFT" is, but the Wiki admins have been known to figure things like this out, especially if it turns out that Ball State University email address in this investigation involving you turns out to establish any connection. So allegations without proof are not only discouraged on Wikipedia but some admins can use browser cookies, IP addresses, and further investigative efforts to find out who made them. Sorry if this was a bad first experience on Wiki (sending an article to AfD as your first Wiki edit, is quite a bold move though!) but you're learning quickly and I've seen many people with a "rough start" go on to become valuable contributors. Dr. Universe (talk) 21:27, 25 May 2021 (UTC)

It is indisputable that the MLR was introduced in the 2007 paper. It doesn't matter whatsoever that there have been corrections and improvements to particular elements of the MLR, or that Google didn't curate that paper into Le Roy's GS profile for whatever reason (this is a major reason why GS is discouraged by NPROF and why I use Scopus). I see more citations (95) for that paper than the 2009 one (80) or the 2008 one by Li and Le Roy (40), so I don't see how you can argue the 2009 one by Le Roy or the 2008 symposium presentation abstract by Dattani is the "real" introduction of MLR that everyone cites. The reasons you give (all the differences between the 2007 and 2009 programs) are completely OR/SYNTH and cannot be used to support anything in the article. JoelleJay (talk) 03:14, 26 May 2021 (UTC)

You say "indisputable" that MLR was introduced in 2007, but what about the 2006 paper which was "receieved on 29 June 2006", whereas Henderson's CV says he began working with LeRoy as an undergrad in May 2006? You say "indisputable", "clear", "obviously", "completely", etc. so much in your AfD discussions, and when someone shows contrary evidence you start badgering them by making them prove every minute detail in excruciating detail (at least you did that to me). Your usage of bold font at times made it appear that you were yelling at me. You said "Google didn't curate that paper" but how do you know it wasn't just taken off by the author himself? The paper does appear on Henderson's GS profile! I haven't (yet) suggested to use OR/SYNTH to support anything in the article, I'm just saying that the edit you made in which you have named an author for a 2007 paper might have been done hastily since the MLR described in the wiki article (for example with y centered around r_reff rather than re) is not actually what is described in the 2007 article. Dr. Universe (talk) 21:57, 26 May 2021 (UTC)

The 2006 paper by Le Roy, Huang, and Jary does namedrop their new Morse/long-range potential form, but its reference is to the then-unpublished 2007 paper where it is actually introduced ("The present work presents a new potential energy function model, what we call the ‘Morse/Long-Range’ or MLR function"). Again, demanding RS to verify important info like who created the model is not nitpicking. It is not badgering to reject symposium abstracts, an anonymous editor's assurance that a particular version of the MLR is the "original" one that everyone thinks of now, or the frankly bizarre suggestion that an author intentionally removed a paper from their GS profile out of embarrassment for an error but then continues to cite that paper for 10+ years. JoelleJay (talk) 05:57, 27 May 2021 (UTC)

@JoelleJay: You said it was "indisputable" that MLR was introduced in 2007, then I showed you that it was introduced in 2006 in a paper submitted 2 months after one of the co-authors of the 2007 paper started his 4-month undergrad internship. You say "It is not badgering to reject symposium abstracts, an anonymous editor's assurance that a particular version of the MLR is the "original" one that everyone thinks of now" — but some of the other things you've been doing are indeed badgering. I also never said the word "original" which you have in quotes. Thanks for pointing out that the author has cited that paper for 10+ years. I hadn't noticed that. It seems Dattani cited it too. You do not need to use phrases like "frankly bizarre". Assume good faith. The error in the paper, combined with GS picking up all of LeRoy's other papers, and GS picking up the 2007 paper on Henderson's profile, was enough to convince me that the author removed it from his profile (that's pretty easy to do for an author's own papers right?). I hadn't thought of checking whether or not LeRoy cited the 2007 paper in subsequent papers 10+ years later. People do tend to do self-citations to raise their h-index and total citation count, but I suppose if he was embarrassed enough to remove it from GS, he'd also be embarrassed enough not to let it see the light of day in more and more publications (unless he feels the benefits of getting more citations outweighs the drawbacks of having it show up in the reference list). You're probably right that he didn't manually delete it from GS. Unfortunately the 2007 paper's MLR definition, is not the one shown in the MLR Wikipedia page, and does not even have the same variables, nor even the right number of parameters! Dr. Universe (talk) 06:38, 27 May 2021 (UTC)

c-state of Li2

@TheLawGiverOfDFT: For the sentence "Two years later it was found that Dattani's MLR potential was able to successfully predict the energies in the middle of this gap" you changed it from "Dattani's MLR" to "the MLR" and wrote "Dattani is relevant to this article, but suspected COI on his addition's when other authors are not addressed. Dr. Universe may be Nike Dattani". I totally understand that it would look bizarre and appear to be due to a COI, if the article says the function was first defined by LeRoy, Dattani and Coxon, then later it says "Dattani's MLR" without naming LeRoy and Coxon. However in that sentence we're not talking about "the MLR" as in "the MLR model" (which is how the wording was in the previous sentence), but we are talking about the 'specific' MLR potential (along with the specific values for each of the optimized parameters) from the paper on which Dattani was first author. The following point (also written by me) actually only mentioned LeRoy's name and not Dattani's at all. In retrospect it would have been better to put "Dattani 'et al.'" rather than just Dattani, but Dattani was first author so gets named before LeRoy here, and Coxon doesn't get mentioned. Dr. Universe (talk) 00:25, 26 May 2021 (UTC)

• If you feel it appropriate to reintroduce it more clearly, that should be fine in my opinion. 00:29, 26 May 2021 (UTC) — Preceding unsigned comment added by TheLawGiverOfDFT (talk • contribs)
  • @TheLawGiverOfDFT: We had an edit conflict since we both tried to comment at around the same time. Here's what I wrote: I'll leave it up to you for now, to decide if you want to change it back to just "Dattani's" or "Dattani and LeRoy's" or "Dattani et al.'s". It's hard to know what I was thinking 8 years ago, but I may have felt the latter two options were too "bulky" (and I still do). In the following point it's okay to say "LeRoy et al. constructed" because we don't have to put the apostrophe and 's' after et al., and since I was mentioning LeRoy's name in the next bullet point, I thought "Dattani's" would look best overall. The citation clearly shows who is an author and who is not, and combined with LeRoy's name being mentioned in multiple other parts of the paper no one is missing out on being mentioned if it says "Dattani's MLR" but I'll leave it to you how you want to change it to reflect that it's a specific MLR function including all parameters set numerically rather than being variables like in the 'general' definition of the MLR model. Dr. Universe (talk) 00:35, 26 May 2021 (UTC)