Timeline for Are exceptions to Klechkowski/Madelung rules understood *theoretically*, or are there known only from *experimental measurements*?
Current License: CC BY-SA 4.0
23 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 15, 2020 at 19:27 | vote | accept | Mathieu Krisztian | ||
| S Apr 15, 2020 at 15:02 | history | bounty ended | CommunityBot | ||
| S Apr 15, 2020 at 15:02 | history | notice removed | CommunityBot | ||
| Apr 14, 2020 at 15:08 | comment | added | Chiral Anomaly | @Ruslan Good point. I didn't notice a clear error-analysis in that report, and the difference is pretty tiny. I wouldn't call it compelling evidence. | |
| Apr 14, 2020 at 15:03 | answer | added | Chiral Anomaly | timeline score: 1 | |
| Apr 14, 2020 at 11:44 | comment | added | Ruslan | @ChiralAnomaly isn't Hartree-Fock method's error in energy much higher than the difference between the configurations we're interested in? This should render HF method useless for making the decision whether given atom obeys the rule or not. | |
| Apr 13, 2020 at 20:30 | comment | added | Mathieu Krisztian | thank you everybody. I think that best answer was : @Chiral Anomaly, in particular for his comment on 2019 commentary and report : maybe you could put that as official answer and I give you the 250 points. Thank you. | |
| Apr 13, 2020 at 13:03 | comment | added | Chiral Anomaly | @MathieuKrisztian Regarding theory: Table 1 in the old report Atomic Structure Calculations I. Hartree-Fock Energy Results... shows total energies of atoms calculated using Hartree-Fock, and for a few of the atoms (including Ce, one of the exceptions), it shows energies of two different electronic configurations, and the rule-breaking config for Ce is just barely lower in energy than the rule-respecting config. Aside from these few checks, the configs themselves seem to be inputs to the calculation rather than outputs, but I'm not sure. | |
| Apr 13, 2020 at 12:55 | comment | added | Chiral Anomaly | @MathieuKrisztian Yes. Empirically, the electronic structure of atoms is inferred from experimental measurements, specifically spectroscopy, and that's how the rule and its exceptions were originally discovered. I can't write a good answer because I don't know the details of how spectroscopy is used to make those inferences. | |
| Apr 13, 2020 at 8:50 | comment | added | Mathieu Krisztian | @Chiral Anomaly : thank you. But then, how do we do know that there are exceptions : from experimental measurements ? | |
| Apr 13, 2020 at 4:11 | comment | added | Chiral Anomaly | @MathieuKrisztian The 2019 commentary "Can quantum ideas explain chemistry’s greatest icon?" (link to pdf), which cites the 2009 report Some solved problems of the periodic system of chemical elements, indicates that the answer is no: the exceptions (and even the rule itself) are not yet fully understood. However, I'm not sure if this is referring only to analytic results or also to numeric computations. | |
| Apr 12, 2020 at 13:13 | comment | added | Mathieu Krisztian | @Chiral Anomaly : I mean that could it be "predicted by theoretical computation", either analytic or numerically. | |
| Apr 10, 2020 at 20:26 | comment | added | BallisticThomist39 | I'm not sure. I'll leave that for the experts around here to answer. | |
| Apr 10, 2020 at 15:27 | comment | added | Mathieu Krisztian | So are exceptions known mostly from experimental results ? | |
| Apr 10, 2020 at 15:26 | comment | added | Mathieu Krisztian | @sven : than kyou | |
| Apr 9, 2020 at 11:59 | comment | added | BallisticThomist39 | Doesn't directly answer your question, but it is possible to predict most of the exceptions to the Madelung rule through Hartree-Fock calculations. See emis.de/journals/SIGMA/2017/038/sigma17-038.pdf | |
| Apr 7, 2020 at 21:00 | history | tweeted | twitter.com/StackPhysics/status/1247630306292764672 | ||
| Apr 7, 2020 at 18:58 | history | edited | Nikita | CC BY-SA 4.0 |
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| Apr 7, 2020 at 15:58 | comment | added | Mathieu Krisztian | @KF Gauss : thank you. Let's see if there are additive comments. | |
| Apr 7, 2020 at 14:01 | comment | added | KF Gauss | I think they are understood theoretically (relavistic effects etc) but for heavier atoms with d and f orbitals it doesn't give nice memorizable rules | |
| S Apr 7, 2020 at 13:48 | history | bounty started | Mathieu Krisztian | ||
| S Apr 7, 2020 at 13:48 | history | notice added | Mathieu Krisztian | Draw attention | |
| Mar 28, 2020 at 16:11 | history | asked | Mathieu Krisztian | CC BY-SA 4.0 |