Chemical Information From the Ehrenfest Force Field Based on Reduced Density Matrix Functional Theory.

ABSTRACT: The Ehrenfest force (EhF) field, which acts on the electron distribution of molecules, offers a force-based framework to probe chemical bonding beyond conventional energy or orbital perspectives. However, its evaluation from correlated wavefunction methods is computationally demanding, limiting applications to small systems. Here we assess Reduced Density Matrix Functional Theory (RDMFT) as an alternative approach to approximate the exchange-correlation contribution to the EhF field. The Fock-Dirac approximation to the pair density from Kohn-Sham pseudo-determinants is also tested. Using a range of natural orbital functionals, we perform a topological analysis of the EhF and its exchange-correlation component in representative molecules from simple diatomics to polyatomic systems. Results

SUBMITTER: Mortera-Carbonell AJ 

PROVIDER: S-EPMC12904097 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature