Quantum mechanical studies of organometallic materials containing the Se-Te bond

This study wa's carried out to establish the reliability of ab-initio (Huzinaga, 3-21G*, STO-3G* basis sets) and pseudo-potential (LANDL2DZ basis set) quantum mechanical methods for molecules containing the Te-Se-Te group. Bond lengths and bond energies were calculated for the diatomic model compounds Se-Se, Se-Te, and Te-Te and for the molecule bis(phenyltelluro) selenide, (C6H5Te)(2)Se. The theoretical results for the diatomic models were compared with the experimental data. The conclusions were: i) the pseudo-potential method is not suited to deal with systems containg Se and Te atoms; ii) the ab-initio method works acceptably with the Huzinaga and the 3-21G* basis sets; iii) the inclusion of electron correlation (MP2) increases the quality of the results; iv) a final choice between the Huzinaga and the 3-21G* basis sets can be made on the basis of new experimental data for molecules with the Se-Te group.