Equipartition theorem
Position density and potential
━━ p(x), left ━━ U(x) = ax², right
Contributions to mean potential energy
Energy above the ground state versus temperature
━━ ⟨U⟩ − U₀ ━━ ⟨H⟩ − E₀ ╌╌ classical T/2 and T
Points mark the selected temperature. Ground-state energy is subtracted here; both curves tend to zero as T → 0.