h i g h l i g h t s• Legendre transform structure for the RFI is obtained with the Hellmann-Feynman theorem.• Inference of the energy-eigenvalues of the SWE-like equation for the RFI is accomplished.• Basis for reconstruction of the RFI framework from the FIM-case is established.• Substantial qualitative and quantitative distinctions with prior studies are discussed.
a b s t r a c tThe (i) reciprocity relations for the relative Fisher information (RFI, hereafter) and (ii) a generalized RFI-Euler theorem are selfconsistently derived from the Hellmann-Feynman theorem. These new reciprocity relations generalize the RFI-Euler theorem and constitute the basis for building up a mathematical Legendre transform structure (LTS, hereafter), akin to that of thermodynamics, that underlies the RFI scenario. This demonstrates the possibility of translating the entire mathematical structure of thermodynamics into a RFI-based theoretical framework. Virial theorems play a prominent role in this endeavor, as a Schrödinger-like equation can be associated to the RFI. Lagrange multipliers are determined invoking the RFI-LTS link and the quantum mechanical virial theorem. An appropriate ansatz allows for the inference of probability density functions (pdf's, hereafter) and energy-eigenvalues of the above mentioned Schrödinger-like equation. The energyeigenvalues obtained here via inference are benchmarked against 301 established theoretical and numerical results. A principled theoretical basis to reconstruct the RFI-framework from the FIM framework is established. Numerical examples for exemplary cases are provided.