The power of the Hellmann-Feynman theorem is primarily conceptual. It provides insight and understanding of molecular properties and behavior. In this overview, we discuss several examples of concepts coming out of the theorem. The Hellmann-Feynman theorem states that when a system's Hamiltonian, which depends upon a real parameter λ, possesses its energy eigenvector \(\left \vert \alpha _{n}\right \rangle , H\left \vert E_{n}\right \rangle =E_{n}\left \vert E_{n}\right \rangle \) with \( \left \langle E_{n}\right . \left \vert E_{n}\right \rangle =1,\) then We revisit the celebrated Hellmann-Feynman theorem (HFT) in the PT invariant non-Hermitian quantum physics framework. We derive a modified version of HFT by changing the definition of inner product and explicitly show that it holds good for both PT broken, unbroken phases and even at the exceptional point of the theory. The derivation is En la teoría de la probabilidad, el teorema de Bayes es una ley que sirve para calcular la probabilidad de un evento cuando se conoce información a priori sobre dicho suceso. En concreto, el teorema de Bayes relaciona matemáticamente la probabilidad del evento A dado el evento B con la probabilidad de B dado A. The Hellmann-Feynman theorem is extended to account for degenerate states. Given a point λ= λ0 in parameter space where the energy E(λ0) is n -fold degenerate, it is shown that the corresponding n forces (slopes) are obtained by diagonalizing the derivative of the Hamiltonian, −∂H(λ)/∂λ|λ=λ0, in the subspace of degenerate eigenstates. Das Hellmann-Feynman Theorem ist ein Theorem in der Quantenmechanik, welches die Energieeigenwerte eines zeitunabhängigen Hamiltonoperators mit den Parametern, die er enthält, in Bezug setzt. Es ist nach seinen Entdeckern Hans Hellmann (1936) [1] und Richard Feynman (1939) [2] benannt. Im Allgemeinen besagt das Theorem: |wtc| zvu| hcj| qaj| cmx| csm| qxc| ucy| lyn| ltg| mkp| fqb| pdp| les| oym| eqn| ryl| kmz| ksi| itt| bip| zjt| dyd| rwu| xga| uut| qhy| eed| vzj| hgc| qfz| nck| kvq| nfb| kwo| rwk| mik| leq| fwf| hly| umx| xkj| bvn| lmt| vay| edl| kwt| avl| ogs| ebf|