Ab initio study of the ground and low-lying states of FeH

The electronic state of FeH dissociating into Fe (5D) and H (2S) have been studied at the restricted open Hartree-Fock (ROHF) and configuration interaction (CI) level of theory, using a relativistic pseudo-potential approach and including or not f functions in the basis set. The relative energies and spectroscopic properties obtained by us are in very good agreement with the experimental results found in the literature. In particular this work provides a new theoretical confirmation of a 4Δ electronic ground state for FeH. The effect of including or not f functions in the basis set is discussed. © 1990 American Institute of Physics.