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    I've reduced the representation consisting of the p orbitals to in (I defined yz as being the plane of the molecule).

    I got the symmetry orbital correctly for and for I got and

    These give the correct energies when you solve the secular equations, but getting the coefficients of the symmetry orbitals to generate the MOs results in some rather messy sums of surds and the like. Is this correct?
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    lol why don't you ask a hard question? :p:

    The allyl radical has three MO's doesn't it? 1 bonding, 1 non-bonding and 1 anti-bonding?

    E_1 = a+\sqrt{2}b => \psi_1 = 0.5\phi_1 + \sqrt{0.5}\phi_2 + 0.5\phi_3



E_2 = a => \psi_2 = \sqrt{0.5}\phi_1 - \sqrt{0.5}\phi_3



E_3 = a-\sqrt{2}b => \psi_3 = 0.5\phi_1 - \sqrt{0.5}\phi_2 + 0.5\phi_3

    or am I completely missing your question?
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    Oh yeah, sorry...I wasn't very clear. I got the correct coefficients for the AOs in the MOs, it was just for the coefficients of the symmetry orbitals I mentioned in the final MOs. They seem a little messy...
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    Yeah, I'm not going to be of much help...sorry
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    No worries...I can work it out by solving simultaneous equations...it just seems strange that it appears to be more calculated to use symmetry to solve it than to just solve the secular equations using the AOs.
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    (Original post by EierVonSatan)
    Yeah, I'm not going to be of much help...sorry
    I realised what I've done...mixed non-equivalent atomic orbitals to make symmetry orbitals. :o: I spent a while trying to work out why the projection operator was "wrong" too...good job I'm getting back into practice.
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    (Original post by Kyle_S-C)
    I realised what I've done...mixed non-equivalent atomic orbitals to make symmetry orbitals. :o: I spent a while trying to work out why the projection operator was "wrong" too...good job I'm getting back into practice.
    Ahh i see, no wonder you were getting odd coefficents...its very easy to get out of practice with things like representation theory, SALCs and the like. I wasn't going to embarrass myself even attempting it :p:
 
 
 

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