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Homework Help: Harmonic Oscillator- Energy levels

  1. Oct 1, 2008 #1
    1. The problem statement, all variables and given/known data

    Predict the wavenumber (cm-1) position of infrared absorption due to fundamental vibration from v=0 to v=1 and 2nd overtone from v=0 to v=3. For a harmonic occilator whose frequency=8.00x1013 s.

    2. Relevant equations

    Energy expression for harmonic oscilator:

    Ev= (v+1/2)hv v=1, 2, 3....

    3. The attempt at a solution

    I am not at all sure of my answers, but this is what I did:

    Fundamental Vibration:

    E0= (0+1/2)*6.626x10-34*8.00x1013 s
    = 2.504 x 10-20

    E1= (1+1/2)*6.626x10-34*8.00x1013 s
    = 7.9512 x 10-20

    E3= (3+1/2)*6.626x10-34*8.00x1013 s
    = 1.85528 x 10-19

    Then I found difference between energies:
    E1-E0=5.4472*10-20 and


    I have no clue how to find the infrared absorption from this. Please help me ASAP. Thanks.
  2. jcsd
  3. Oct 1, 2008 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    You need the equation for energy of a photon of a particular wavelength. Your book or professor must have given you this, in order to be asking this question.

    Another question, do you know what the units are for the energies you calculated?
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