Prediction section, flow diagram

This section recalls very briefly the basic concepts necessary for the discussion. Electron tunneling has been established for several decades in vacuum [23] as well as in solid-state structures [24]. Quantum mechanics predicts that electrons can flow between two conductors separated by a distance of the order of 20 A. The energy diagram of a tunneling junction is sketched in Fig. 1 a. From the Bardeen tunneling... 

An understanding of interaction diagrams is not absolutely necessary for using the principle of electron flow to predict organic reaction products. However, it is useful for understanding reactivity trends and the stability of reactive intermediates. This section relies on the principles discussed in Section 1.6, An Orbital View of Bonding. 

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