Within the bonded tableau unitary group approach (BTUGA), a scheme, combined with Pauling抯 resonance theory to select the predominant valence bond structures for VB calculations, is proposed. This scheme ensures a re...Within the bonded tableau unitary group approach (BTUGA), a scheme, combined with Pauling抯 resonance theory to select the predominant valence bond structures for VB calculations, is proposed. This scheme ensures a reliable and illustrative bonding picture in the description of chemical reactions, as exemplified by the isomerization reaction HNCHCN. The computation results account for important bonding features about this isomerization at the ab initio level and explore the mechanism of phenomena such as (i) HCN is more stable than HNC; (ii) the C-N bond first lengthens and then shortens in the vicinity of the transition state; (iii) only H-atom migration is observed in the isomerization process, without the breaking of the CN bond. Our results demon-strate that only a few bonded tableau functions are sufficient enough to provide a visual and reli-able bonding picture.展开更多
基金supported by the Key Project of Ministry of Education for Science and Technology(Grant No.20021002)the Major Key Project of Natural Science Foundation of Fujian Province(Grant No.2002F010).
文摘Within the bonded tableau unitary group approach (BTUGA), a scheme, combined with Pauling抯 resonance theory to select the predominant valence bond structures for VB calculations, is proposed. This scheme ensures a reliable and illustrative bonding picture in the description of chemical reactions, as exemplified by the isomerization reaction HNCHCN. The computation results account for important bonding features about this isomerization at the ab initio level and explore the mechanism of phenomena such as (i) HCN is more stable than HNC; (ii) the C-N bond first lengthens and then shortens in the vicinity of the transition state; (iii) only H-atom migration is observed in the isomerization process, without the breaking of the CN bond. Our results demon-strate that only a few bonded tableau functions are sufficient enough to provide a visual and reli-able bonding picture.
