Tagged Questions
4
votes
3answers
140 views
Do electrons in multi-electron atoms really have definite angular momenta?
Since the mutual repulsion term between electrons orbiting the same nucleus does not commute with either electron's angular momentum operator (but only with their sum), I'd assume that the electrons ...
1
vote
1answer
120 views
Searching the point group of symmetry
I am engaged in the field of quantum-chemical calculations using programs written by myself. I have found out that I have a problem in finding the point group symmetry of the molecule.
The first idea ...
2
votes
1answer
180 views
Electric dipole transitions/expectation value of position
Part of a homework question asks to show that for $\ell=0$ in both $\Psi_i$ and $\Psi_f$, we have
$$
\int \Psi_i^\ast \vec{r} \Psi_f \; d\tau = 0
$$
for the position vector $\vec{r}$. (This is for ...
7
votes
3answers
2k views
What makes the difference between ionic and covalent bonds?
Backstory: When I learned about chemical reactions, there were two types of molecular bonds: Ionic, where an atom or compound molecule with a low valence number loses those valence electron(s) to one ...
2
votes
1answer
2k views
Why is oxygen in a triplet state and what are the consequences?
From Wikipedia here and here:
''Almost all molecules encountered in daily life exist in a singlet state, but molecular oxygen is an exception.''
''The unusual electron configuration prevents ...
4
votes
3answers
340 views
Nanorobots. What stops us from producing them yet?
If we can already predicts accuratelly motion on molecular levels, what stops us from developing small robots to, for instance, navigate through our blood vessels looking for cancerous cells and ...
5
votes
2answers
790 views
Is the Mendeleev table explained in quantum mechanics?
Does anybody know if there exists a mathematical explanation of Mendeleev table in quantum mechanics? In some textbooks (for example in "F.A.Berezin, M.A.Shubin. The Schrödinger Equation") the authors ...
8
votes
3answers
511 views
What is the angular momentum spectrum of an sp${}^3$ electron?
So, one thing has been annoying me ever since I learned about orbital hybridization: you explain the shape of molecules by postulating that the orbitals of multi-electron atoms are linear combinations ...
6
votes
2answers
291 views
Explaining valence with quantum mechanics
Can anyone give me a quantum mechanical explanation of the theory of valence? (i.e. why atoms bond just enough to have a complete orbital)
EDIT: To clarify, I already have an idea of why atoms bond, ...
