While 2D coupling diagrams can effectively depict bonding in many cases, some molecules call for 3D representation. Even in cases where 2D coupling diagrams are sufficient, seeing the availability of potential bonding sites—or the absence thereof—is conveyed more effectively with color-coded occupations than with dots.

Here are 3D coupling diagrams for hydroxyl radical (OH), water, and hydrogen peroxide (HOOH). One can expect OH to be more reactive than the closed shell species due to its obvious radical character. The 3D version of the HOOH coupling diagram depicts the non-planar nature of its bonding (which arises from the nature of the bonding of ground state triplet O₂).

The next figure shows the formation of triply bonded N₂ from very reactive nitrogen atoms.

The next figure shows the 3D version of the linear s-p hybridized glyph and the 3D coupling diagrams for BeH and BeH₂.

Finally, here are 3D coupling diagrams for both of the states of CH and CH₂ treated in §4 as well as the coupling diagrams for CH₃ and CH₄:

§8 describes the Molecule Projects I assign to students for different Physical Chemistry courses.