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Benoit Creton coauthored research on electron counting.^[ref]

Electron counting records metal valence electrons plus ligand donations using a declared convention. In ionic counting, subtract metal oxidation state from its group number, then add donor electrons; in neutral counting, combine neutral metal and ligand fragments consistently. An Fe–Fe single bond contributes one electron to the count at each metal.

Use the neutral-fragment skeletal count: each AlMe supplies two electrons, each CEt supplies three and the bridging H supplies one. HenceThere are 13 nonhydrogen skeletal vertices, eight Al plus five C, and $16=n+3$ pairs. In the usual PSEP classification this is therefore arachno, corresponding to a 15-vertex closo parent with two vertices absent. The μ${}_4$-H cap contributes an electron but is not counted as a carbon-like skeletal vertex. The aluminium cube is a convenient subframework; its eight corners alone are not the complete Wade skeleton. Calculations on capped cubic carbaalanes likewise identify 16 skeletal pairs for the five-carbon-cap/one-hydride-cap case.^[ref]