Evaluation of Effective Core Potentials and Basis Sets for the Prediction of the Geometries of Alkyltin Halides

A systematic comparison of the optimized geometries of five organotin compounds, Cl n Sn(CH3)4 - n , n = 0−4, with the available gas-phase electron diffraction results is reported. All optimizations were carried out with the B3LYP density functional method. Comparison of 10 basis sets and three effective core potentials leads to the conclusion that the combination of the SDB-aug-cc-pVTZ basis set and the LANL2 effective core potential for tin, together with the 6-31G(d,p) basis set for the other atoms, is recommended for the prediction of the geometries of organotin compounds.