# What is the criteria for bound states

• I
I read this wiki and some of the references
https://en.wikipedia.org/wiki/Bound_state

But I can't really understand. For example the electron in hydrogen has specific energies and not general relations that the articles seem to claim.

Thanks

## Answers and Replies

mfb
Mentor
For example the electron in hydrogen has specific energies and not general relations that the articles seem to claim.
The specific energies of hydrogen are special cases.

What is unclear?

What is unclear?

What is the criteria for bound states?

mfb
Mentor
They can't have enough energy to fall apart.

They can't have enough energy to fall apart.
Ok thanks. But I am still not clear, do you mean potential or kinetic, and how is the binding energy calculated from them.

edit: It also seems to be potential specific as in this paper
https://arxiv.org/pdf/hep-ph/0407258.pdf

mfb
Mentor
I mean the total energy.

How to calculate the binding energy of a specific system depends on that system.

How to calculate the binding energy of a specific system depends on that system.

I guess my question is again what makes this binding energy unique as opposed to any other interaction energy that may arise.

Nugatory
Mentor
I guess my question is again what makes this binding energy unique as opposed to any other interaction energy that may arise.
The only thing that's unique about it is that we've decided to call it "binding energy".

If you solve Schrodinger's equation for a potential that vanishes at infinity, you will find that some of the eigenstates vanish at infinity and some do not. We call the ones that do vanish at infinity "bound states", and we call their energy eigenvalues "binding energy".