All Questions
14
questions
-2
votes
1
answer
199
views
Why can s and p orbitals of one atom form hybrid orbitals but the overlaping of s & p orbitals of two different atoms don't form a molecular orbital?
So my question is in the title : Why can s and p orbitals of one atom form hybrid orbitals but the overlapping of one s orbital and one p orbital (perpendicular to the bond axis) of two different ...
- 59
3
votes
0
answers
74
views
Energy of d(x²-y²) and d(xy) orbitals the same with respect to trigonal symmetry?
In the orbital splitting diagrams of trigonal planar and trigonal bipyramidal complexes the d$_{x² - y²}$ and d$_{xy}$ orbitals have the same energy. I have always assumed that this is because they ...
- 286
3
votes
2
answers
388
views
Determination of energies in MO diagrams
How do we determine the relative placements of molecular orbitals in their diagrams? I understand that we can use point groups to find symmetry-allowed interactions between orbitals that we write on ...
3
votes
1
answer
118
views
Do SALC-AOs really belong to their symmetry species?
I'm working through a molecular symmetry textbook and something keeps nagging at me. If I derive the SALC-AOs for NH3 (using the projection operator method), I'll get
A1: $ \frac{1}{\sqrt{3}}(\...
- 33
1
vote
0
answers
101
views
Why sigma bond has C2 symmetry not C∞?
I have seen some books indicated sigma bond has C2 symmetry. I understand pi and delta bond change their signs about C2 and C4 rotation about bond axis, but I don't understand why sigma bond has C2 ...
- 21
1
vote
2
answers
3k
views
What is the symmetry of dxy orbital?
Considering the sign of orbital and assuming the $z$-axis as a principal axis, for me, it looks like that it has two perpendicular $C_2$ axes that penetrate the lobes, so I think it is $C_\mathrm{2v}$....
- 21
2
votes
0
answers
139
views
How do computational chemistry programs determine the irreducible representation of a molecular orbital?
I was coding a simple RHF code to test my understanding of computational chemistry when I stumbled upon this question. How exactly do computer programs like Gaussian, GAMESS-US etc. know which ...
- 1,105
3
votes
1
answer
136
views
Spatial Wavefunction Symmetries and Identical Particles
I was reading this and it mentions in the 3-electron section, that for a spacial wave function to be symmetric under fermion swapping, it must be a function of even parity. Similarly for anti-symmetry ...
- 133
2
votes
1
answer
191
views
How do I have to interpret the input to the OCC flag in Molpro?
I'm trying to understand the occupied orbital specification in Molpro. They're specified by the OCC flag, while it's stated in the documentation, that
OCC, m1, m2, ..., mn;
where the ...
- 1,267
3
votes
1
answer
2k
views
What kind of bonds can form between benzene and transition metals in π-complexes?
I'm trying to draw the six π-orbitals (3 bonding, which are filled, and 3 anti-bonding) of a benzene ring when it complexes with metal d-orbitals and which metal orbitals have the correct symmetry ($\...
- 41
6
votes
3
answers
3k
views
Why does symmetry have to be maintained in molecular orbitals?
Using the example of $\ce{XeF4}$:
What is the physical explanation enforcing the symmetry of the $\ce{1b_{1g}}$ orbital on the fluorine atoms? Why isn't the symmetry of a nonbonding orbital arbitrary?...
- 1,648
5
votes
0
answers
159
views
Finding the irreducible representation which an orbital transforms under [duplicate]
I have some major confusion on irreducible representations. An example of a problem I have is
Based on the character table for the point group of each of the follwing molecules, which irreducible ...
- 4,535
17
votes
1
answer
25k
views
How can I find the symmetry labels of atomic orbitals in a molecule?
What are the symmetry labels for the p and d orbitals of platinum in $\ce{[PtCl4]^2-}$?
I understand how to find the point group of a molecule, but am not sure how to use the character table to find ...
- 944
34
votes
1
answer
10k
views
When is it true that more nodes equals higher energy?
Consider all the MOs of some isolated molecule. (It could be a single
atom too; I'll use MO to refer to AOs as well.) Number them in
increasing order of the number of nodes (node = surface where the ...
- 2,747