Ok so I am trying to expand my understanding of these two concepts. Here is what I understand so far.(adsbygoogle = window.adsbygoogle || []).push({});

There are very few Schrodinger Equations that are exactly solvable

Both Theories are used to approximate a solution

Perturbation Theory utilizes a similar function with a known solution and adds the small perturbation to bring the answer closer to the actual value of the solution for the unsolvable wave function.

Variational Theory takes a trial wave function and sets up a set of parameters, a1, a2, etc and results in a value Ev. Ev is always larger than E, the actual ground state energy. Adjusting the parameters to minimize Ev will bring you closer and closer to the actual value of the ground state energy, for your actual wave function, E.

Is this correct and can any one expand on what I have here? I understand how to do the actual mathematics involved but am a little shaky on why I am doing them. Also if anyone has a clear definition of how the variational principal relates to Huckle theory I would really appreciate it.

Thanks

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# Perturbation and Variational Theory

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