Ab initio metods have been employed to investigate first row transition metal hydrides and helides of form: TMHⁿ⁺(where n=0–2) and TMHeⁿ⁺(where n=1–3), respectively. Multi-configurational SCF and IC-MRCI methods have been used, along with all-electron ROHF-UCCSD(T) methods, in order to compare trends in the bonding of these series. Equilibrium geometries, dissociation energies and vibrational frequencies have been determined for the low-lying electronic states. A comparison with the diatomic first row transition metal hydrides illustrates the limit of isoelectronic approaches and so further highlights the unique binding properties of helium.
Physical Chemistry Chemical Physics Vol. 5, p. 252-258