Find the energy from the graph of the wave function

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SUMMARY

The discussion centers on determining the kinetic and potential energy of a quantum system using the wave function graph Ψ(x). The kinetic energy operator is defined as ##\displaystyle {-{\hbar^2\over 2m}\nabla^2}##, which relates to the second derivative of the wave function, Ψ''(x). Eigenfunctions of the Hamiltonian yield eigenvalues that represent the total energy, which is the sum of kinetic (T) and potential energy (V). To isolate potential energy, both the second spatial derivative and the time derivative of the wave function are necessary.

PREREQUISITES
  • Understanding of quantum mechanics principles
  • Familiarity with wave functions and eigenfunctions
  • Knowledge of the Hamiltonian operator in quantum systems
  • Basic calculus, specifically derivatives
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  • Explore methods for calculating potential energy from wave functions
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Students and professionals in quantum mechanics, physicists analyzing wave functions, and anyone interested in the relationship between wave functions and energy in quantum systems.

HastiM
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Hello,

I am wondering if it is possible to determine the kinetic energy and potential energy of a quantum system just by investigating the graph of its wave function. Suppose we are given the graph of some wave function Ψ(x), i.e. a function which is an eigenfunction of the hamiltonian. I think its second derivative Ψ''(x) should somehow correspond to the kinetic energy of the particle. Is that right? What about the potential energy?

Best regards
 
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Yes, ##\displaystyle {-{\hbar^2\over 2m}\nabla^2} ## is the kinetic energy operator.

Eigenfunctions of the Hamiltonian have eigenvalues corresponding to the total energy ##T+V## .

So, only if you have the second spatial derivative and the time derivative can you deduct ##V##
 

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