Undergrad Do neutral atom collisions affect the continuous nature of black body radiation?

[Getterdog]

I’ve read everything I can here and in the stack exchange on the topic of the continuous nature of black body radiation and it’s been really helpful,but I’m lead now to this question. Do neutral atom collisions shift the eigenfunctions,during the collisions? Do collisions create temporary dipoles? I’m Assuming no free electrons,just collisions in neutral atoms.thanks jk

 

[Jilang]

I assume by not free you are regarding an electron as belonging to some atom or another. In an interaction it is not so clear cut.

 

[DrClaude]

Do neutral atom collisions shift the eigenfunctions,during the collisions? Do collisions create temporary dipoles?

Yes to both. The van der Waals interaction leads to the polarisation of two atoms that are not too far from each other. This can be seen as shifting the energy levels with respect to the isolated atom.

 

[hilbert2]

I’ve read everything I can here and in the stack exchange on the topic of the continuous nature of black body radiation and it’s been really helpful,but I’m lead now to this question. Do neutral atom collisions shift the eigenfunctions,during the collisions? Do collisions create temporary dipoles? I’m Assuming no free electrons,just collisions in neutral atoms.thanks jk

In some collisions we can think of the wave function of the two-atom system as a product of the wave function for the internal motion in the atoms (relative position of electrons w.r.t. the nuclei) and a wave function for the center of mass motion of the atoms. Then you can model the collision in a way where the internal motion eigenstates change temporarily when the atoms get close enough to interact. In some other cases the two atoms can form a bound state, as in the recombination of two chlorine atoms to form a $Cl_2$ molecule - then you can't write the final state wavefunction in the same way as a combination of separate atoms because there's a covalent bond formed.

 

[Getterdog]

In some collisions we can think of the wave function of the two-atom system as a product of the wave function for the internal motion in the atoms (relative position of electrons w.r.t. the nuclei) and a wave function for the center of mass motion of the atoms. Then you can model the collision in a way where the internal motion eigenstates change temporarily when the atoms get close enough to interact. In some other cases the two atoms can form a bound state, as in the recombination of two chlorine atoms to form a $Cl_2$ molecule - then you can't write the final state wavefunction in the same way as a combination of separate atoms because there's a covalent bond formed.

Does this then account for the more or less continuous distribution of energy for a monoatomic nonionized substance? Thanks jk