Particle in a 3D box (Quantum)

Click For Summary
The discussion focuses on calculating the degeneracies of the first four energy levels for a particle in a 3D box with dimensions a=b=1.5c. The energy levels are derived using the equation Exxnynz=h2/8m(nx2/a2+ny2/b2+nz2/c2), leading to specific values for the first four levels. There is confusion regarding the calculation of degeneracies, particularly in how quantum numbers contribute to energy levels. One participant questions the method of multiplying by (1+1+3/2) in the calculations, emphasizing that quantum numbers should be integers. The conversation highlights the importance of correctly applying quantum mechanics principles to determine energy levels and their degeneracies.
breeg
Messages
1
Reaction score
0

Homework Statement



What are the degeneracies of the first four energy levels for a particle in a 3D box with a=b=1.5c?

Homework Equations



Exxnynz=h2/8m(nx2/a2+ny2/b2+nz2/c2)

For 1st level, the above = 3h2/8m
For 2nd level, the above = 6h2/8m
For 3rd level, the above = 9h2/8m
For 4th level, the above = 11h2/8m

The Attempt at a Solution



I think I finally grasped the basis of what the problem wants.

For the 1st level:

Exxnynz=(h2/(8m*1) + h2/(8m*1) + h2/8m*(1/1.5))*(1+1+(3/2))

So E1 1 3/2

3/2 was obtained because 1/1.5 is 2/3=c because a=b=1=1.5c so c=1/1.5=2/3

Is this correct? I'm just unsure about the rest of the energy levels. It seems like one can just pick numbers and force it to work so I'm lost on the proper degeneracy.
 
Physics news on Phys.org
breeg said:
For the 1st level:

Exxnynz=(h2/(8m*1) + h2/(8m*1) + h2/8m*(1/1.5))*(1+1+(3/2))

Why are you multiplying by (1+1+3/2)? I don't think you've got the idea. The quantum numbers each take on an integer value, and that is why the energy levels are different.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
Replies
46
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 12 ·
Replies
12
Views
842
  • · Replies 5 ·
Replies
5
Views
1K
Replies
14
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
17
Views
4K