0
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0answers
42 views

Why is the orbital angular momentum of a pi electron along the axis of two atoms' molecule one?

I'm reading quantum chemistry. The book says that the orbital angular momentum of a $\pi$ electron along the symmetry axis of a molecule made up of two atoms is $\pm 1$. I think this is a primary ...
0
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0answers
24 views

Difficult to visualize Franck-Condon overlap

The franc condon principle says about the vertical transitions, means the coordinates of the nuclei remains unchanged during an electronic transition. But, what is the physical meaning or how to ...
0
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0answers
56 views

What is the physical meaning of multiplicity of an electronic state in a molecule?

When we specify the electronic states, we specify its multiplicity as well. If S is the spin quantum number, then 2S+1 is the corresponding multiplicity. Two states having same L value but with ...
1
vote
5answers
278 views

What laws (formulas) govern forces between atoms?

What laws (formulas) govern the fundamental forces of nature? For example, gravity is governed by the inverse-square law. I am thinking about how particles attract each other, but also repel. All ...
4
votes
2answers
84 views

Why is it energetically favourable for molecular bonds to form from a QM point of view?

For example, if you have two hydrogen atoms and an oxygen atom, they are all electrically neutral and don't attract each other. But then if they manage to get "close enough" somehow they snap together ...
1
vote
1answer
57 views

Difference between photo electron spectrum and photoelectron angular distribution

I am trying to learn the Photoelectron velocity map imaging. While I was going through the article "Chem. Soc. Rev., 2009,38,2169-2177", it is said that the "photoelectron spectrum reflects the energy ...
0
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0answers
128 views

Breaking of a covalent bond

When a bond between two atoms is broken, why only one electron is released. Why not two? (as two electrons make up a covalent bond.)
0
votes
1answer
79 views

Thermionic emission, delayed emission and predissociation

In molecular photodissociation, the thermionic emission, delayed emission and predissociation are the same? otherwise, what is the difference between them? My question is not about the solids, but I ...
1
vote
1answer
338 views

Why it is called a Newton Sphere? (Velocity map imaging)

In velocity map imaging (photo-dissociation and photo-emission), the ejected particles form a newton sphere. I didn't really get the concept why it is called a "newton sphere" and also why at the ...
2
votes
1answer
352 views

Explanation on Atomic Orbitals and Molecular Orbitals

We were reading about atomic structures and bond making and my teacher told me that when two atoms are fused or when they make bond, two orbitals are formed. 1-Bonding Molecular Orbital & 2- ...
9
votes
4answers
1k views

Does it exist a free good molecule / atom simulation software?

I'm looking for a software or software package (for example C/C++) that can simulate a lot (say thousands at least) of molecules in action (ie. in movement or attached to say static walls). I have ...