Quantum Mechanics, one-dimensional box problem

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The discussion focuses on the one-dimensional box problem in quantum mechanics, specifically determining the energy eigenfunctions and eigenvalues with boundaries at -a/2 and a/2. The wavefunction is given as Phi(x) = Asin(kx) + Bcos(kx), with continuity conditions at the boundaries requiring Phi(-a/2) = Phi(a/2) = 0. To find the wave number k, participants emphasize the importance of periodicity conditions, which lead to the allowed k values and subsequently the energy spectrum. Clarification is sought regarding the notation, suggesting Psi may be more appropriate than Phi. The overall goal is to derive the correct eigenfunctions and energy levels for the specified boundaries.
danai_pa
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What are the energy eigenfunctions and eigenvalues for the one-dimensional box problem describ above if the end of the box are at -a/2 and a/2

I can find the solution of this problem Phi(x) = Asin kx + Bcos kx
and property of wavefunction is continuous at boundary
Phi(x=-a/2) = Phi(x=a/2)=0
but i don't understand to find k (wave number), please help me
 
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danai_pa said:
What are the energy eigenfunctions and eigenvalues for the one-dimensional box problem describ above if the end of the box are at -a/2 and a/2

I can find the solution of this problem Phi(x) = Asin kx + Bcos kx
and property of wavefunction is continuous at boundary
Phi(x=-a/2) = Phi(x=a/2)=0

What is the problem "described above"?

And do you perhaps mean Psi instead of Phi ?
 
Can you sketch your eigenfunctions?
(I'm assuming you've done the box problem with ends x=0 to x=a. Hopefully you realize that the choice of origin shouldn't change the shape of the eigenfunctions.)
See any pattern? any grouping of the eigenfunctions?
 
The periodicity conditions shouls give you the allowed "k" values from which you can get the energy spectrum.

Daniel.
 
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