Recent content by Nezva

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    Inorganic I - 8 Coordinate Complexes

    In square antiprism the squares to not overlay each other, they are staggered 45 degrees. But thank you for showing me antiprisms, very neat structures to try to do molecular symmetry on. A dodecahedron has too many coordinates from what I see but also an interesting structure. The...
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    Inorganic I - 8 Coordinate Complexes

    Main question: What is the name of the 8 coordinate complex pointgroup? Or does it even exist? I've been exposed to octahedrons and icosohedrons, however, the 8 coordinate high symmetry complexes appear to have been skipped. I'm aware that these complexes would be rare but I think that...
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    Expectation Values and Operators

    Thank you both for the contrasting notations. Is there anything I can do to return the help? =\sum_n\sum_m c_n^*c_m a_m\langle\psi_n,\psi_m\rangle=\sum_n|c_n|^2 a_n Very elegant. The absolute value of the complex conjugates is a clever touch. I've not used complex number enough to...
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    Expectation Values and Operators

    What do you mean by substitute the 'entire' \Psi and \Psi*, simply that I didn't denote the first wavefunction with asterisks fully? Or do you mean literally put in c21, c2, c3, etc.? Anyways here was an attempt at this. \int(c^*_n\Psi^*_n\hat A)(\hat Ac_n\Psi_n) c^*_n...
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    Operator Terminology: What Does the Asterisk Mean?

    The \Psiis linear combination of n orthonormal eigenfunctions of the linear operator, A(hat). What effect does a normalized function vs a 'orthonormal' function have on the 'expectation value'? Sorry I'm being thrown into this terminology very rudely. Any help is greatly appreciated.
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    Operator Terminology: What Does the Asterisk Mean?

    \int c*n\Psin \left| A(hat) \right| cn \Psin
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    Expectation Values and Operators

    \int c*n\Psin \left| A(hat) \right| cn \Psin I'm having trouble putting subscript into the LaTex format, is there a way to do this without breaking pup the tex formatting?
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    Operator Terminology: What Does the Asterisk Mean?

    I'm trying to substitute the psi function into the expectation value. I do not understand how to use the asterisk in this case. Especially if the constants in the function are complex... I'm trying to understand the concept and am unsure what to ask.
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    Operator Language: Why d/dx*x - x*d/dx = 1

    Thanks for stating it so clearly and concisely. Many issues were resolved.
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    Expectation Values and Operators

    I've never seen an expectation value taken and would greatly appreciate seeing a step by step of how it is done. Feel free to use any wavefunction, this is the one I've been trying to do: In the case of \Psi=c1\Psi1 + c2\Psi2 + ... + cn\Psin And the operator A(hat) => A(hat)\Psi1 =...
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    Operator Terminology: What Does the Asterisk Mean?

    In the case of \Psi=c1\Psi1 + c2\Psi2 + ... + cn\Psin And the operator A(hat) => A(hat)\Psi1 = a1\Psi1; A(hat)\Psi2 = a2\Psi2; A(hat)\Psin = an\Psin Calculate: \left\langle\Psi\left|A(hat)\right|\right\Psi\rangle
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    Understanding Ladder Operators

    So that's where that comes from ;) I'm having trouble identifying all the equations from very similar ones. You seem to have a keen grasp of QM, where did you learn from? Some kind of organization in this maelstrom of QM ideas and variables would be nice... I've seen similar ideas but never...
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    Operator Language: Why d/dx*x - x*d/dx = 1

    When linear operators A and B act on a function ψ(x), they don't always commute. A clear example is when operator B multiplies by x, while operator A takes the derivative with respect to x. Then which in operator language means that To get the last equation they divided through by ψ...
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    Understanding Ladder Operators

    Thanks for the clarification. It's a measurement of the extent to which they do NOT commute, correct? I do not see where a non-zero commutator would be useful though.
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    Understanding Ladder Operators

    Does LzLx = LxLz ? I want to know if the relations hold true for both of them or if I have to add a negative sign (or something of that nature). Don't angular momentums commute?
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