Talk:Electron orbital

I realize that the whole Periodic Table argument may carry on indefinitely. I wonder if anyone can confirm whether there is any point in continuing the work I started below (or if it is even relevant):

- Well.... we already have several periodic tables elsewhere on Wikipedia. This article should be about Electron orbitals. -- Tarquin 19:32 17 Jul 2003 (UTC) - Yes, I know. I should have made it more clear that I was proposing a format... I realize that the Periodic Table will contain slightly different information. -- sugarfish 19:44 17 Jul 2003 (UTC)

I certainly believe that tabular data belongs in the article, to show by element which orbitals are occupied. My own shoice would be to avoid repeating the standard periodic table and go with a simpler layout, with entries like 2-8-2. That said. we certinly need some kind of article and expansion of atomic shells. Keep up the good work, Lou I 19:51 17 Jul 2003 (UTC)

I've included enough information to explain the main points regarding the topic. The table needs some coloring I think, according to the periods that the elements belong to. Let me know -- sugarfish 08:31 18 Jul 2003 (UTC)


 * I like the vertical table with the orbital numbers. very nice! -- Tarquin 09:18 18 Jul 2003 (UTC)

What's all this about K-Q? No class I've ever taken has used that nomenclature. It's simpler to index orbitals by principal quantum number $$n$$, so that "K" is 1, "L" is 2, "Q" is 7, etc.

Furthermore, it would be more enlightening to further separate the electron distributions by quantum number $$l$$, thus: 1s, 2s, 2p, 3s, 3p, 4s, 3d, etc.

Another question. This article seems woefully bare. I can't bring myself to believe that not a single one of the many Wikipedists with any chemistry education at all has noticed this article's pitiful condition. Unless someone explains to me exactly what is the matter here, and where the real article on electron orbitals lives, I'll have to redo this whole thing myself from the ground up. --Smack 21:50, 21 Sep 2004 (UTC)

revision
I've related the electron orbitals page properly to quantum mechanics and revised the page to make it focus on the generality of orbitals and link to wavefunction. Can someone move the periodic table Talk to somewhere more appropriate - such as Periodic Table? It doesn't belong under electron orbitals, which, from how it appears in atomic and molecular orbitals, is giving a basic background to orbitals. Next stage is to revise atomic and molecular orbitals...--Ian 15:26, 29 Jan 2005 (UTC)

Complete vs. time-independent wavefunctions
I have some idea of the distinction between the full form of a wavefunction (Ψ) and the form that it takes after the time-dependent term is divided out (ψ), but I don't really have the knowledge to sort it out and make the article consistent and accurate. Could someone take care of this? --Smack (talk) 05:03, 31 Mar 2005 (UTC)

Merge with atomic orbital?
Dear editors,

I really believe this page should be merged with atomic orbital.

What is an electron orbital if it is neither an atomic nor molecular orbital?

Moreover many errors are spoiling this article.

For example, it is not correct that an electron in an atom or a molecule has a quantized energy. This is the atom or the molecule which does! It is only a first (Hartree-Fock-type) approximation to consider that each electron is described by a one-electron Hamiltonian.

I have tried first to correct this article but now I don't see at all why one should try to.

I am awaiting your comments.

17:49, 14 July 2005 (UTC)


 * I believe that all three orbital articles have merit and should be retained. This article should be a general introduction to the subject, while the other two deal with the specifics of the two types of orbitals.  As for electrons having quantized energy, you're correct in a way, but in another way, I think you're wrong.  An orbital is a one-electron wavefunction, so it does have a quantized energy.  The fact that an electron occupies a linear combination of orbitals is only tangential to an introductory discussion.


 * I understand that you have legitimate reasons to want to merge this page, but I would like to insistently discourage you from using page merges as a relatively quick and easy alternative to rewrites. --Smack (talk) 02:19, 15 July 2005 (UTC)


 * P.S: Please describe the "numerous errors" over which you repeatedly removed a section of the article. --Smack (talk) 02:25, 15 July 2005 (UTC)


 * You are right an orbital is a one-electron wavefunction but this is by noway a reason for its energy to be quantized. One-electron wavefunctions can be time-depending wave packet or scattering states, i.e. with scattering boundary conditions ($$\Psi \approx e^{-i\vec{k} \cdot \vec{r}} + f e^{ikr}$$ for large r), or even non normalized Siegert functions ($$\Psi \approx f e^{ikr}$$ with complex valued k for large r).  In fact in general an orbital is not an eigenfunction of a Hamiltonian.  It is just a one-electron wavefunction used in the expansion of the many body wave function in term of Slater determinants.  One can choose it how one wants in order that the Hartree-Fock limit is satifactorily reached and the many-body configuration interaction expansion of the wave function converges fast to its full CI limit. In practice one often use the Hartree-Fock method which defines orbitals as eigenfunctions of the Fock operator.  Expanding this equation in a set of square integrable wave functions (see Roothaan equations) leads to quantized energies (Koopman's theorem energies -- which are different of the usual definition of energy expected values) but this is just due to the fact that the basis set is not large enough to span the continuous spectrum of the Hamiltonian.  I think the lately re-written article on molecular orbital is more or less free from faulty judgments.  I suggest you to read it carefully.  But if you still don't agree have a look at good text books like Szabo and Oslund (SZABO A. and OSLUND N.S. (1989), Modern Quantum Chemistry: Introduction to Advanced Electronic Structure Theory, New York, McGraw-Hill).


 * You ask me to point out the plenty errors I have observed in the math section. Let me just tell you a simple one : the probability density is not $$\Psi^2$$ but $$|\Psi|^2$$.


 * Moreover for me an electron orbital is by noway a key concept (since it can only be defined in the context of atomic or molecular orbital) and should not be the topic of a wiki article. I suggest to change it into a disambiguation page pointing to atomic and molecular orbital articles. 147.231.28.83 08:57, 15 July 2005 (UTC)


 * What you say is true (to the extent that I can judge) of general one-electron wavefunctions, but it is my understanding that non-eigen wavefunctions are not considered orbitals. --Smack (talk) 03:28, 16 July 2005 (UTC)
 * P.S: It is also my understanding that wavepackets, linear combination solutions, etc. are also not considered orbitals. As for the status of orbitals as a trivial special case of wavefunctions, I guess you're right, but many non-orbital wavefunctions are transitory, as they depict moving particles. --Smack (talk) 03:31, 16 July 2005 (UTC)


 * You are fully right but when you say An orbital is a one-electron wavefunction, so it does have a quantized energy you are not correct.  Moreover orbitals must not be eigenfunction!  They can be chosen arbitrarily such that they span the relevant Hilbert space and the configuration interaction expansion converge fast.  They are usually chosen as the Fock operator eigenfunctions but other methods exist!Vb 08:22, 18 July 2005 (UTC)