Localized Electron Model for Molecules

This qualitative model for the chemical bond describes molecular structure with localized valence electrons. Valence electrons repel each other strongly when they are close to each other in the same shell on one atom and have the same spin. The Linnett model for the bond is based on the recognition that electron correlation exists, which means that the position or the path of a valence electron strongly depends on the positions of the other valence electrons. 

This is not the same as in orbital models. The correlation energy is in the first approximation ignored in orbital models where the average position of the other electrons is used to estimate the potential of each individual valence electron. The effect of correlation is introduced in orbital models as a refinement in a quantum-mechanical calculation by mixing excited states in with the ground state using the 

The Linnett model assumes that localized valence electrons form bonds for the usual reason lowering of energy. Linnett electrons behave as follows  

The valence electrons remain on atoms, repel each other in the atomic shells, and position themselves as far as possible from one another in their shells. 

Electrons have spin two electrons having opposite spin repel each other much less than electrons with parallel spins, which behavior follows directly from the Pauli principle in quantum mechanics (Section 2.10). 

---