Ab initio calculations on the [Rh(PH<inf>3</inf>)<inf>3</inf>Cl] system. Influence of the basis set on the structural and reactivity trends of transition-metal complexes

Six all-electron and pseudopotential basis sets have been used to characterize theoretically the model square-planar [Rh(PH3)3Cl] complex by means of ab initio calculations. The quality of the basis sets has been assessed by looking at optimized geometries, atomic charges and orbital energies. Other criteria considered were non-zero gradients, atomic charges and orbital energies obtained from calculations using the experimental geometry. Results obtained at optimized and experimental geometries have been compared and discussed. A quantification of the computational cost (processor time and disk space) for the series of basis sets has been carried out, a tentative classification having been made.