CALIBRATION AND BENCHMARKING OF MODEL CORE POTENTIALS - APPLICATIONS TO SYSTEMS CONTAINING MAIN-GROUP ELEMENTS

The recently developed model core potentials for the main-group elemen ts were used in a systematic investigation of their reliability and pr edictive power in the studies of the prospective ligand building block s for organometallic complexes. The molecules studied include: homonuc lear diatomics (Group VB: N-2, P-2, As-2, Sb-2 and the halogens: F-2, Cl-2, Br-2, I-2); heteronuclear diatomics (CO analogues XY, where X = C, Si, Ge, Sn, and Y = O, S, Se, Te; and interhalogen compounds); tria tomic hydrides AH(2) (OH2, SH2, SeH2, TeH2), triatomic oxides (CO2 and SO2), tetra-atomic hydrides AH(3) (NH3, PH3, AsH3, SbH3), tetra-atomi c analogues of NF3, and small hydrocarbons (C2H2, C2H4, CH2). Molecula r geometries were optimized using a modified Powell method of searches along conjugate directions and the results compared with experimental data. Electron correlation effects were studied at the MP2 and CISD l evels. (C) 1998 Elsevier Science B.V. All right reserved.