Homonuclear diatomic molecules correlation diagram for

FIGURE 8.6 Orbital correlation diagram for homonuclear diatomic molecules of the transition metals... 

Fig. 3.5 displays Mulliken s [2] generalized orbital correlation diagram for homonuclear diatomic molecules, which has been of seminal importance for the elucidation of the electronic structure of molecules. Only the atomic levels n = 1,2 have been included on its right on the left, the orbitals of the united atom have been extended sufRciently that all of the necessary correlation lines can be drawn. The energetic spacing of the AOs is purely schematic, their order on the left being that common to silicon and sulfur, the united atoms corresponding to N2 and O2. The abcissa, is - of course - quite non-linear. 

Figure 20.12 Correlation Diagram for Homonuclear Diatomic Molecules.

Consider the correlation diagram for homonuclear diatomic molecules (Fig. 1.10), constructed in the same way as that for Hj. The significance of the non-crossing rule becomes apparent when we consider the details of this diagram. In terms of symmetry the Og 2s molecular orbital could correlate with either the 2s- or the 3s-orbital of the united atom. Similarly the Og 2p molecular orbital could correlate with either the 2s or the 3s united atom orbital. As a consequence of the non-crossing rule, the correlation of the... 

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