How Do You Solve the Schrodinger Equation with Spherical Coordinates?

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KingBigness
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Homework Statement



See attached photo


The Attempt at a Solution



So I have no idea if I have even started this problem correctly so any help would be nice.

My working is set out in one of the pictures.

Any help would be appreciated I really am not quite sure what to do. Can't figure out where the x^2-y^2 comes from.

Thank you!
 
Attachments
  • Printed text stating the Schrödinger hydrogen atom wave function for n = 3, l = 2, m = ±2 in spherical coordinates, with the normalised radial and angular factors and exponential, and the instruction to form the real orbital 3d(x²−y²) from the linear combination (d+1 + d−1)/√2.
    Screen shot 2011-08-23 at 11.41.26 AM.png
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  • Four stacked lines of handwritten-style mathematics: wavefunction expressions in spherical coordinates with factors 1/sqrt(2), 1/(162 sqrt(pi)), (1/a0)^(3/2), r^2/a0^2, e^(-r/(3a0)), sin^2(theta), and e^(±2i phi) terms, ending with a line containing x^2 + y^2.
    Screen shot 2011-08-23 at 12.02.41 PM.png
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Hi KingBigness! :wink:
KingBigness said:
Can't figure out where the x^2-y^2 comes from.

I'm guessing really, since this isn't my field :redface:, but if you replace r2sin2θcos2φ by r2sin2θ(cos2φ - sin2φ), that looks like x2 - y2 :smile:
 
Leave the r2 alone for now and use the fact that[tex]\cos \theta = \frac{e^{i\theta} + e^{-i\theta}}{2}[/tex]to get rid of the complex exponentials.
 
Thank you both for that, I shall try that and let you know how I go
 
Ok I tried that and out came the x^2-y^2

Thank you for that tip.

This is the answer I have ended up with can you let me know if it is correct or if I need to simplify it more? not really sure when to stop =\
 
Attachments
  • Handwritten derivation on lined paper: [e^(2iφ) + e^(-2iφ)] sin²θ becomes 2cos(2φ) sin²θ, then 2[cos²(2φ) - sin²(2φ)] sin²θ, with a right triangle labelled r, x, y, and 2[x² - y²] sin²θ boxed, followed by 'My Answer'.
    photo.jpg
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I lied above...I brought the sin theta squared in before I converted which got rid of the sin theta squared in the final answer.

Is this now correct?
 
Yes, that's right, because in spherical coordinates x = r sin θ cos φ and y = r sin θ sin φ.
 
vela said:
Yes, that's right, because in spherical coordinates x = r sin θ cos φ and y = r sin θ sin φ.

Sweet finally got this question complete!

Thank you. Will double check all my algebra later to make sure I haven't done a silly mistake.

Thanks again for your help