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What is the energy of a particle

  1. Nov 2, 2014 #1
    When we do a standard QM calculation we get energy eigenvalues. So, for example in the ground state of a hydrogen atom, does that energy value include the mass-energy of the particle. Does it include the thermal energy? Or is it just the kinetic plus potential energy?
  2. jcsd
  3. Nov 2, 2014 #2
    It includes whatever is included in the Hamiltonian. For the most basic hydrogen atom this is just kinetic energy and electric potential energy.

    Note that thermal energy is not a property of individual particles. Thermal energy in thermodynamics or statistical mechanics is part of an approximate description of systems of many particles.
  4. Nov 2, 2014 #3
    I see. Thanks
  5. Nov 2, 2014 #4


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    Staff: Mentor

    You could add the mass-energy manually (just by adding mc^2 to the Hamiltonian).

    If you calculate the energy with relativistic quantum mechanics, you automatically include the mass-energy in the Hamiltonian.
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