Molecular orbitals angular momentum properties

Bonds with r < dl < d[ become possible because of nuclear screening (increased bond order), which causes concentration of the bonding pair directly between the nuclei. The exclusion limit is reached at d = t and appears as a geometrical property of space. The distribution of molecular electron density is dictated by the local geometry of space-time. Model functions, such as VSEPR or minimum orbital angular momentum [65], that correctly describe this distribution, do so without dictating the result. The template is provided by the curvature of space-time which appears to be related to the three fundamental constants tt, t and e. 

The symmetry of molecular systems with non-zero spin will be taken up in three stages We begin with an elementary discussion of the symmetry properties of spinning electrons and follow it with a few words about how the net spin of the electrons in a molecule affects its state symmetry. Then, in preparation for the analysis of thermal reactions in which electron spin is not conserved, we will consider how the overall symmetry of a reacting system can be retained by compensatory changes in spin- and orbital-angular momentum. [2, Chaps. 3-5]... 

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