Particle in a 3D box (Quantum)

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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). The calculated energy levels are E1 = 3h²/8m, E2 = 6h²/8m, E3 = 9h²/8m, and E4 = 11h²/8m. The confusion arises regarding the proper application of quantum numbers and their contribution to degeneracy, particularly in the first energy level calculation.

PREREQUISITES
  • Understanding of quantum mechanics principles, specifically the particle in a box model.
  • Familiarity with the Schrödinger equation and energy quantization.
  • Knowledge of quantum numbers and their significance in determining energy levels.
  • Basic algebra and manipulation of equations involving physical constants like Planck's constant (h) and mass (m).
NEXT STEPS
  • Study the derivation of energy levels for a particle in a 3D box using quantum mechanics.
  • Learn about the significance of quantum numbers in determining degeneracy and energy states.
  • Explore variations of the particle in a box model, such as different boundary conditions.
  • Investigate the implications of degeneracy in quantum systems and its applications in statistical mechanics.
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Students and educators in quantum mechanics, physicists working on quantum systems, and anyone interested in the mathematical modeling of particles in confined spaces.

breeg
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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.
 
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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.
 

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