A STUDY OF THE C-LI BOND IN METHYLLITHIUM AND OF THE POTENTIAL-ENERGY SURFACE FOR BOND BREAKING
- 化学化工－已发表论文 
An ab initio valence bond study of the potential energy surface for methyllithium, with special reference to dissociation by symmetric stretch of the C-LI bond, has been performed and compared with previously published results. New calculations using many-body perturbation theory (MBPT at the MP4 level) and coupled-cluster methods with all singles and doubles (CCSD) have also been made for comparison purposes. The VB description of the bond in terms of one covalent and two ionic structures is found to be highly satisfactory throughout the whole dissociation process: the ionic character of the bond is about 38% at equilibrium, going smoothly to zero above about 4 Angstrom, while the energy curves are competitive with the MP4 and CCSD curves and appear to give an excellent general description of the bond-breaking process.