The Three-electron Bond with Four or More AOs

THE THREE-ELECTRON BOND WITH FOUR OR MORE AOs 

The equivalence that exists between the MO and VB resonance descriptions of the three-electron bond is only exact when one AO per centre is used to accommodate the electrons. This has been discussed in some detail by Murrell and Ralston [34], and elaborated further in VB calculations for a variety of systems by Hiberty and coworkers [8(a),35]. However, when four or more AOs are used to accommodate the three electrons, the VB structure XII or XIII may still be associated with an orbital wavefunction, and an extended VB-MO equivalence may be developed [36]. We shall use H2 to demonstrate this result for the simplest case, which involves the use of four AOs to accommodate the 

Further development of this type of approach - in particular with 

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