Valence bond configurations

This is a simple example of valence bond configuration interaction. 

It is beyond the scope of this chapter to review the numerous attempts to model 8, 2 reactivity. Besides models describing the reaction qualitatively in terms of valence bond configurations and mostly aiming at interpreting substituent effects, anomalous Bronsted slopes and appearance of intermediates on the reaction pathway (see Pross, 1985 8haik, 1985, and references therein), essentially two types of quantitative treatments have been developed. The more rigorous one, based on ab initio quantum chemical calculations (Berthier et al., 1969 Jorgensen, 1988) has reached quantitative... 

McLennan, D. J. Pross, A. The mechanism for nucleophilic substitution of a-carbonyl derivatives. Application of the valence-bond configuration mixing model./. Chem. Soc. Perkin Trans. 2 1984, 981-984. 

W. Wu, L. Song, Z. Cao, Q. Zhang, S. Shaik, J. Phys. Chem. A 106, 2721 (2002). Valence Bond Configuration Interaction A Practical Valence Bond Method Incorporating Dynamic Correlation. 

VALENCE BOND CONFIGURATION MIXING DIAGRAMS GENERAL FEATURES... 

VALENCE BOND CONFIGURATION MIXING DIAGRAM WITH IONIC INTERMEDIATE CURVES... 

Valence Bond Configuration Mixing Diagram for Proton-Transfer Processes... 

Insights from Valence Bond Configuration Mixing Diagrams One Electron Less-One Electron More... 

VBCI Valence bond configuration interaction. A VB computational method that starts with a VBSCF wave function, which is further improved by CI. The Cl involves virtual orbitals that are localized on exactly the same regions as the respective active orbitals. There are a few VBCI levels that are denoted by the rank of excitation into the virtual orbitals, for example, VBCISD involves single and double excitations. 

The trends in the activation barriers were explained440,442 using the valence bond configuration mixing model443 444, as shown schematically in Figure 32a. According to this... 

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