A perturbation operator problem

[einstein1921]

hi,my friends.I have a perturbation operator problem.
v=ezE;
why this formula is right?how to deduce it?a is bohr radius.
thank you!

 

[mfb]

You could add more context to your question.
<2s|V|2p,m=0> can be evaluated if you know how the orbitals look like. It is an integral which (probably) gives the result 3eaE.

 

[einstein1921]

You could add more context to your question.
<2s|V|2p,m=0> can be evaluated if you know how the orbitals look like. It is an integral which (probably) gives the result 3eaE.

thank you!2s 2p orbital is the hydrogen atom orbital ,they are degenerate.
thank you again!