Talk:Relativistic quantum chemistry

Color of Copper

Does it mean that also color of metallic copper originates from relativistic effects involved? —Preceding unsigned comment added by 83.13.170.66 (talk) 14:54, 27 January 2010 (UTC)

No, without relativistic effects, the colour of the metals, Cu, Ag, Au would go from copper colour to silver colour down the column of the periodic table. The relativistic effects apply only to heavy elements and change only the colour of Gold here. --Bduke (Discussion) 21:26, 27 January 2010 (UTC)

Too vague. And the explanation for Color of Gold is poor compared to concise explanation for liquidity of mercury: The electronic transition from the 5d orbital to the 6s orbital is responsible for this absorption. Well, yes, but that doesn't explain WHICH wavelengths are absorbed -- what is the actual mechanism that affects visible light? Martindo (talk) 00:22, 8 September 2023 (UTC)

Don't assume readers know what you know

The article currently has a sentence that says:

s and p electrons travel at a significant fraction of the speed of light and the second being that there are indirect consequences of relativistic effects which are especially evident for d and f orbitals

Would someone who knows what "s and p electrons" and "d and f orbitals" are please link to wikipedia articles explaining them. The purpose of an encyclopedia is to help people learn so just because these are familiar to experts doesn't mean every reader will know. Thanks. 68.110.104.80 (talk) 12:05, 9 July 2010 (UTC)

There's no easy way to link s and p electrons per se, but I have linked atomic orbitals where these concepts are explained. Usually we assume that anybody reading an article like this one should have read the Schrodinger equation and atomic orbital wikis first. Relativistic quantum chemistry is not much fun to read about if you don't know anything about relativity, quantum theory, or chemistry, first. ;) SBHarris 16:46, 9 July 2010 (UTC)

I reworded "s and p electrons" as "electrons in s and p atomic orbitals", which is more accurate anyway, and allows a to link to atomic orbitals here too. I also revised the intro to the Atomic orbitals article to place a little more emphasis on the meaning of s orbitals etc.

However I agree with SBHarris's other point. This is really an advanced article aimed at readers who have studied at least general chemistry and already know the basics of atomic orbitals. We can try to make it a little more accessible to readers with no scientific background, but we may not have too much success. Dirac66 (talk) 18:18, 9 July 2010 (UTC)

Confusing statement

The article says:

"Heavy elements" in this context refers, typically, to elements in the lower region of the periodic table...

Should that read "elements in the higher region"? —Preceding unsigned comment added by 86.184.107.217 (talk) 14:12, 28 February 2011 (UTC)

They are higher (larger) in atomic number, but physically always lower on the actual periodic table, which has light elements above, heavy ones below. SBHarris 16:20, 28 February 2011 (UTC)

Oh, OK, thanks. Gosh, that is terribly confusing. We really ought to change that wording... 86.176.211.68 (talk) 00:17, 1 March 2011 (UTC)

Later versus earlier works for me- no confusion there —Preceding unsigned comment added by 71.127.246.177 (talk) 05:36, 22 March 2011 (UTC)

I changed 'physically lower' to 'later'; 'physically lower' is precise and correct but nevertheless too easy to be misunderstood, I think.Felix116 (talk) 18:02, 9 June 2011 (UTC)

I do NOT agree that "lower" is correct. There are MANY ways to imagine its layout, lower Atomic Numbers at Top Left is only one of them (but the most common). This is clear by looking up the article on alternative arrangements of the Periodic Table. "Lower in the Periodic Table" is factually WRONG at worst and sloppy at best; "Lower in the commonly displayed Periodic Table" corrects that.Abitslow (talk) 09:27, 22 December 2013 (UTC)

While the Actinides are indeed some of the heaviest elements of the periodic table, the Lanthanides are all between barium and hafnium and ARE NOT amongst the heaviest elements - common elements like tungsten, gold and lead are all heavier. It is more correct to say that the heavy elements are located at the bottom of the periodic table than to single out the lanthanides and actinides as being the heaviest. — Preceding unsigned comment added by Turricanfan (talk • contribs) 21:45, 30 April 2014 (UTC)

Guys… there are heavier and lighter elements. Their atomic numbers are greater and smaller (or less) respectively. Don’t invent freaking ad hoc “higher/lower” terminology which can sow anything but confusion. Incnis Mrsi (talk)

Update

• Pyykkö, Pekka (2012-05-05). "Relativistic Effects in Chemistry: More Common Than You Thought". Annual Review of Physical Chemistry. 63 (1): 45–64. doi:10.1146/annurev-physchem-032511-143755.

--Makecat_Talk 03:29, 7 August 2012 (UTC)

AU / AG required or just elitist?

RE: Color of gold and caesium

Is it maybe just elitism to refer to gold and silver repeatedly as Au or Ag? What would be the negative effect to the article if it were Gold and Silver. Is this a resource for chemists or a resource for people? I think that where possible Wikipedia argues for accessibility. While I understand which is which it is unsure if a generic reader would do so and it is questionable if it is even required when not identifying specific atoms. Pizik (talk) 19:09, 12 January 2013 (UTC)

I see no reason not to call them by their names - David Gerard (talk) 22:23, 12 January 2013 (UTC)

Agree. Just don't capitalize silver and gold. There is no elitism in avoiding error. SBHarris 10:48, 13 January 2013 (UTC)

Unfortunately “elitism” is a kind of profanity in Wikipedia. But I know than “AU” and “AG” have an incorrect case in this context and I am proud of my elitism. Incnis Mrsi (talk) 20:43, 11 August 2019 (UTC)

Bohr Model

I can't believe anyone can seriously write about the "predictions" of the Bohr Atomic Model using relativistic corrections. Its been discredited for 50 years. I challenge the entire section invoking it. Its my understanding (I am not well versed in it) that the entire approach to atomic orbitals must change when relativity is included: it is NOT a simple perturbation. (eg. nodes disappear with the inclusion of time-dependence (which is what velocity is, last I heard)). The ONLY way the Bohr Model can be used is to severely limit where and how it is used. How is it meaningful to speak of the velocity of the electron in a bound quantum state??? This surely can not be mainstream! Abitslow (talk) 09:37, 22 December 2013 (UTC)

Agree! I do not understand the meaning of "electron velocity" in a quantum context. This should be explained clearly! Dirac quotation, too, is inappropriate and misplaced. The quotation says "it is, indeed, usually sufficiently accurate if one neglects relativity variation of mass and velocity..." (bold is mine). It is indeed usually sufficiently accurate, in fact only a few exceptions are mentioned in the article. 78.15.165.142 (talk) 00:22, 1 August 2015 (UTC)

I put an "expert needed" template. I hardly know anything about physics, but I'm put off by the statement that the fine structure constant is "a relativistic correction for the Bohr model". Also I think we need to justify simply plugging relativistic mass into the Bohr radius formula - isn't mass a function of velocity which is a function of kinetic energy which is a function of potential energy which is a function of the Bohr radius? If it's really OK to ignore the latter relationships then I think the article it should cite something peer-reviewed for this, or at least a textbook. A5 (talk) 01:30, 9 August 2018 (UTC)

electrons in s and p atomic orbitals travel at a significant fraction of the speed of light

The article says: electrons in s and p atomic orbitals travel at a significant fraction of the speed of light. It seems to me that this is true for the inner shells of heavier elements, not the outer, 5s for example, or the inner shells of light elements. Can we say 1s and 2p here? Gah4 (talk) 16:30, 4 April 2019 (UTC)

@Gah4: IMHO dependence on Z and n can’t be expressed in few words. As you already mentioned, for Z = 19 neither 3s nor 3p nor 4s have significant relativistic influences. But for some Z = 113 all its 7s, 7p, and 6d are significantly relativistic – in most places where the electron resides the electric field is much stronger than could be created by a Z = 19 nucleus without any shielding at all. Incnis Mrsi (talk) 20:55, 11 August 2019 (UTC)

Yes it is more complicated, which is what I didn't say so well, and yes there is no easy way to say it. Pretty soon you have to figure out what is significant. Outer s electrons of high Z elements will sometimes, but not all that often, see mostly screened nuclear field. That may or may not be significant. Atomic orbital has some discussion about relativistic effects, and of element 137. Gah4 (talk) 04:54, 12 August 2019 (UTC)

v ≈ Zc/137

The article says" v ≈ Zc/137. While that is true for smaller Z, there needs to be a relativistic correction at larger Z. Since the whole article is about relativistic corrections, we shouldn't need to correct the corrections. Gah4 (talk) 16:35, 4 April 2019 (UTC)

If you started to italicize Z, then do it consistently. By the way, italicized numerals look u7t3r1y unprofessional. Incnis Mrsi (talk) 20:43, 11 August 2019 (UTC)

Quotes are in italics, for some reason that I don't know. One Z was a quote from the article, the other wasn't. Gah4 (talk) 04:23, 12 August 2019 (UTC)

s

OK, the 1s electrons are always close to the nucleus, and so most affected by relativity. Other s electrons, unlike p, d, f, and g, also have an antinode at the nucleus, and so also see the nuclear charge. They will be shielded for much of the time (that is, much of their probability density sees less nuclear charge), but still have the effect. For 2p, with a node at the nucleus, there will be much less effect. Gah4 (talk) 16:54, 4 April 2019 (UTC)

Mercury is a monomer?

Maybe it is, I'm not an expert. But the article on monomer does not lead me to think that it is. It would be nice if this were clarified here or in the monomer article. The article on mercury does mention a polymer containing an ion containing mercury. — Preceding unsigned comment added by 2607:FCC8:C944:9300:FF5B:BAEA:5D6B:59B (talk) 12:30, 4 December 2019 (UTC)

Relativistic mass, electron velocity, "Qualitative treatment"

The notion of relativistic mass is not taken seriously by modern physicists: the mass is a scalar invariant that does not depend on reference frame. It is certainly not "one of the most important and familiar results of relativity"! This concept should likely be avoided altogether.

The notion of electron velocity also seems quite sketchy; what does it even mean in the context of an atomic orbital? Without positions, velocity as a concept is borderline. If something more rigorous like momentum or energy is meant, that should be said. Why the velocity scales as $Z$ is also not explained. Overall the "Qualitative treatment" section's value is questionable. 50.217.2.10 (talk) 19:24, 20 January 2023 (UTC)