Calculating Lowest Energy Levels of a Rigid Spherical/Cubic Box

quantumdude10
Messages
4
Reaction score
0

Homework Statement



Determine the four lowest energy levels, their degeneracies and quantum numbers of the wavefunctions for an electron in

i) a rigid spherical box of 2 Angstrom radius and,

ii) a rigid cubic box of the same volume

Express the result in multiples of ħ2/(2m0a2), and in electron Volt units. Plot the result on energy level diagrams and comment.


Homework Equations


Schroedinger's equation in spherical coordinates...


The Attempt at a Solution



Not sure how to solve 3d questions...
 
Physics news on Phys.org
Welcome to Physics Forums.

How about we start with writing out Schrodinger's equation with the laplacian in spherical coordinates.

Do you know what the usual ansatz is for 3D spherically symmetric problems?
 
you mean this one?

is there a way to post those equations to the body directly and not as an attachment?
 

Attachments

  • SchroedingerSpherical.gif
    SchroedingerSpherical.gif
    3.8 KB · Views: 512
quantumdude10 said:
you mean this one?
That's the one. Now, do you know the appropriate ansatz?
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top