Talk:Aufbau principle

message: I didn't know there was so much lore about the electron orbital space locations but I've thought about a hierarchial process of dividing cubic space around a center point and would like to express an opinion. Which is that cubic space can be considered as either an accumulation of spheric spaces or as an accumulation of cubic volumes and in the case of atomic orbital volumes we assume that the volumes be analyzed and accumulated are cubic volumes. So in the case of the volume around the center of the atom we cut the big cube into three parts in all three orthogonal directional directions and can wind up with 27 equal small cubes within the big cube which can be numbered from 1 to 27 with number number 14 being the center small cube. Then there is a space hierarchy in the proximity of the small cubes to the central cubes consisting in decreasing proximity; (1) the 6 side connected cubes, (2) the 12 edge connected cubes, and (3) the 8 corner connected cubes. Now you would think that a partition of the space around the center of an atom or whatever would be partitioned in accordance with some logical consideration of these subordinate cubic space volumes but but they dont and give me doubts about there physical practicality.WFPMWFPM (talk) 02:10, 29 August 2008 (UTC)
thread_title: Division of cubic space

message: The article claims "In fact, it was formulated by Niels Bohr along with Simons, Wolfgang Pauli and Reuhrer.", but I find no one of that name in Wikipedia, and in Google it looks like stuff derived from here.
This reference is already in the original version of this article from 2005-03-03 10:50.
I tried googling "bohr simons pauli aufbau", but  without success, and "Ruehrer" and "Ruhrer" also did not help.
Heinrich Rohrer sounds far more plausible, but his autobiography does not mention it.
PJTraill (talk) 16:51, 3 October 2008 (UTC)
replies: text: Sorry, I misread the history, it does not appear until http://en.wikipedia.org/w/index.php?title=Aufbau_principle&diff=212283663&oldid=211909146 by 122.161.83.146  , where it looks very like schoolboy spam. It is amended in http://en.wikipedia.org/w/index.php?title=Aufbau_principle&diff=next&oldid=218158901 by 122.161.10.29 to reintroduce Bohr and Pauli, but without removing the junk, although the spelling is changed. It seems evident that "Simons" and "Reuhrer" are spam, and I am removing them. PJTraill (talk) 17:21, 3 October 2008 (UTC)
thread_title:  Simons and Reuhrer appear to be spam 

message: It is evidently not Aufbauprinzip, which is not an article such as http://de.wikipedia.org/wiki/Aufbauprinzip!
It is curious that this article does not have a German equivalent, and I get the impression that this is because "Aufbau principle" is a name for a collection of rules, formulated by different people at different times.
Is this the case, and is there no German expression for the same idea?
PJTraill (talk) 16:56, 3 October 2008 (UTC)
replies: text: Aufbauprinzip is used in German for this concept, but not as frequently as I expected German-language Google search. Atombau ("atom building")is much more common German-language Google search, and is the term originally used by Bohr. Perhaps the general meaning of Aufbau is too present for German speakers, in the same way that English-speakers don't use the term "construction principle" or "structure principle"… German Wikipedia describes the Aufbau principle at :de:Elektronenkonfiguration in the section headed Auffüllen der Schalen ("Filling (up) of the shells"). Physchim62 (talk) 08:40, 6 October 2008 (UTC)
thread_title:  What is the German for "Aufbau principle"? 

message: When I search the term "diagonal rule" it ought to bring me to this article.
:Above edit by 70.112.31.144 on 2013 Nov 06.
::This is a good suggestion as many teachers use this name informally. I have now added a redirect here from Diagonal rule, and also mentioned the name diagonal rule in the article, with a source. Dirac66 (talk) 22:19, 8 November 2013 (UTC)
thread_title:  This is also called the "diagonal rule" 

message: Substituted at 08:35, 29 April 2016 (UTC)
thread_title: Assessment comment

message: :
:Could you explain the reason for changing the configurations in the Madelung rule section from filling order (based on sequences of neutral atoms such as K, Ca, Sc, Ti, V, Cr) to leaving order (based on ionization sequences such as Cr, Cr+, Cr2+, Cr3+, ...)? From the viewpoint of quantum mechanics, 3d54s1 and 4s13d5 are completely equivalent. But from a pedagogical viewpoint, the Madelung rule describes the sequence of configurations of neutral atoms, so I think it is clearer to write the configurations in order of filling neutral atoms. Dirac66 (talk) 00:23, 9 December 2018 (UTC)
replies: text:  Unless I am very much mistaken, it has always been standard to write them in leaving order; at least, that's what I remember from school (even when the Madelung rule was being taught). Greenwood and Earnshaw, for example, writes them all in leaving order, and that's also how they appear in all our element infoboxes. Double sharp (talk) 00:37, 11 December 2018 (UTC)
replies: text:  Thank you. Some books do use filling order, such as Miessler and Tarr (2nd ed, p.38). To help readers who may have seen filling order elsewhere, I suggest we start with one atom which is not an exception (say Ti) and mention that both notations (3d24s2 and 4s23d2) are equivalent, with a link to Electron configuration#Notation for more explanation. Then we can use only leaving order for all the exceptions. Dirac66 (talk) 18:20, 11 December 2018 (UTC)
replies: text:  OK, done. As an example of a book using leaving order, I used Jolly because I don't own Greenwood and Earnshaw. Dirac66 (talk) 01:57, 2 January 2019 (UTC)
thread_title:  Leaving order vs. filling order 

message: I recently edited this article to clear up some terminological confusion.
There also seemed to be confusion as to the status of the Madelung Rule. Is it an approximation? Is it a rule? Do some of the elements have anomalous configurations or is it the Madelung Rule that has anomalies?
Certainly the elements in question are not anomalous. Their electron configurations are an outcome of the interaction of Nature’s laws. These laws are thought to be elegant but the outcome of their interactions are usually not elegant given the irregularities we see in the world all around us.
The Madelung Rule is unusual. Sure it does not correctly predict the electron configurations of 20 elements out of 118. But if you arrange the elements in one long line and then count forward comparing the actual configurations with those predicted by the Madelung Rule you will see that after each incorrect electron configuration or configurations the Madelung Rule returns to predicting the right electron configuration. If the MR was a true approximation it should always be off by a small margin, or after scoring some early successes it should go further and further off target. But it doesn’t behave like that.
The only way I’ve been able to explain what is occurring is by way of a metaphor: “These exceptions [to the Madelung Rule] can be viewed as turbulence along a flight path; once passed the flight path returns to normal.”
It seems like the MR is the spine of the periodic table in terms of the electron configurations of the elements. There are some kinks along the way due to some unaccounted for additional interactions between the rules of Nature. But the core is there.
The literature on the nature of the Madelung Rule is effectively non-existent.
All of the above is based on my reading of the literature on the Madelung Rule, and discussions with chemists, and periodic table researchers and aficionados.
If anyone has a better way of clarifying the nature of the MR so as to clear up the folklore and misunderstandings about it, feel free to chime in.
I believe this is not OR as I doubt it would be challenged, since if it was removed, it would make the explanation of the MR less clear. I also feel this is a case meriting we ignore the OR rule, if that’d be called for, and as there is scope for doing. Sandbh (talk) 12:25, 13 July 2019 (UTC)
replies: text: Sorry, but unless you can find a reliable textbook or scientific paper which relates electron configurations to turbulence and flight paths, the analogy must be considered as original research. I have found a brief discussion in Jolly's inorganic text, with a mention of a paper by D.P.Wong in Journal of Chemical Education on the topic. I will include these sources in the article as a start. Dirac66 (talk) 01:38, 16 July 2019 (UTC)
thread_title:  Exceptions as turbulence along a flight path 

message: The classical electronic Madelung rule becomes apparent when the periodic table's periods are laid out in a Left-Step manner, after Charles Janet, from the late 1920's. In this depiction the order of appearance of each new orbital type in turn is the primary motivation rather than surface chemical behavior. The s-block elements thus appear on the RIGHT edge of the table, so the sequence is: 1s, 2s; 2p3s, 3p4s; 3d4p5s, 4d5p6s; 4f5d6p7s, 5f6d7p8s.  The n+l rule shows that for each orbital in these recast periods, the sum is always the same within any one period.
The spherical atomic nucleus, under a simple quantum harmonic oscillator model (probably also what motivates the Janet Left-Step periodic table), also shows a left-step motif-the individual orbitals  contain the same number of particles as the electronic ones.
The sequence is numbered differently by convention: 1s, 1p; 1d2s, 1f2p; 1g2d3s, 1h2f3p; 1h2g3d4s; 1j2h3f4p- this is because, unlike the electronic system, all the orbitals within a shell here are of the same parity. In the electronic left-step system, each period/shell length occurs twice: 2,2; 8,8; 18,18; 32,32. In the spherical nuclear system, on the other hand, it is the number of ORBITALS within a shell that occurs twice: 1,1; 2,2; 3,3; 4,4. In electronic periods/shells orbital parity alternates.
With the spherical nuclear shells, the equivalent of the Madelung rule is 2n+l rather than n+l as in the electronic system.
1s> 2(1)+0=2; 1p> 2(1)+1=3; 1d2s> 1d> 2(1)+2=4, 2s> 2(2)+0=4; 1f2p> 1f> 2(1)+3=5 2p> 2(2)+1=5; 1g2d3s> 1g> 2(1)+4=6, 2d> 2(2)+2=6, 3s> 2(3)+0=6; 1h2f3p> 1h> 2(1)+5=7, 2f> 2(2)+3=7, 3p> 2(3)+1=7; 1i2g3d4s> 1i> 2(1)+6=8, 2g> 2(2)+4=8, 3d> 2(3)+2=8, 4s> 2(4)+0=8; 1j2h3f4p> 1j> 2(1)+7=9, 2h> 2(2)+5=9, 3f> 2(3)+3=9, 4p> 2(4)+1=9.
Ellipsoidally deformed harmonic oscillator nuclei have different shell structures from that of a sphere, but the Madelung rule analogue is still based on the one outlined above, but with corrections. These corrections themselves are based on the oscillator ratio of the deformed nucleus, which determines how many times each orbital size are used, and their relative placements in the shell structure.
2601:89:C601:C3B0:4D70:9AF6:620E:94F6 (talk) 18:11, 24 May 2021 (UTC)
thread_title:  Equivalent Madelung/diagonal rule for spherical atomic nuclei 

message: Is "Uncle Wiggly path" actually in widespread use (at least in education), or is it just one guy's joke that happened to end up in a journal article from the 60s (or 80s)? If it's the latter, then I think its inclusion here is unencylcopedic and undue. Also, should it be "Uncle Wiggily" in reference to the children's book character? And is the information for the reference even correct? The doi takes me to an article from the 1980s by a different author. – Scyrme (talk) 20:36, 9 February 2023 (UTC)
replies: text: Yes, I agree with you. This is a childish name which is not used seriously, and I will now delete it from the article. The other names given are more scientific. Dirac66 (talk) 21:14, 9 February 2023 (UTC)
replies: text:  Fair enough. I didn't want to just cut it immediately, since I saw that it's been listed in the article for a number of years (since 2019) and didn't want to cut something that might be helpful to young students (assuming use in schools, perhaps in North America), but I was probably being too cautious. – Scyrme (talk) 22:03, 9 February 2023 (UTC)

text: Agree. If it is indeed used in schools, we need a citation for that anyway.  Qflib, aka KeeYou Flib (talk) 04:16, 11 February 2023 (UTC)
thread_title:  "Uncle Wiggly path" 

message: The Jolly book calls this thing the "Madelung rule". What is the ref which calls it "Aufbau"? Johnjbarton (talk) 17:36, 23 February 2024 (UTC)
replies: text: Ok I found several and added one to the article. Bohr came up with the empirical rules but his atom model struggled to match them. Pauli's exclusion helped. Madelung was based on Thomas fermi atom. Johnjbarton (talk) 18:13, 23 February 2024 (UTC)
thread_title:  Reference for "Aufbau principle"