Basis set influence on the ab initio description of the dihydrogen complex [Os(PH₃)₂Cl(CO)H(H₂)] ¹

Systematic RHF calculations on the [Os(PH3)2Cl(CO)H(H2)] complex with eleven different basis sets are presented. Among the basis sets considered there are examples of valence double-ζ quality and of valence triple-ζ quality, as well as examples containing diffuse and polarization functions and examples without them. The comparison of the optimized geometries and the total energies leads to the definition of a hierarchy of basis set qualities for the computation of the structure and reactivity of transition metal complexes.