Harmonic oscillator model of aromaticity (HOMA) in conjugated radicals and cations

Comparison of Various Theoretical Measures of Aromaticity within Monosubstituted Benzene

“…Another family of quantifications are based on the tendency of an aromatic system to equalize its internal bond lengths. The most popular of these protocols, the harmonic oscillator model of aromaticity (HOMA) [19][20][21], evaluates deviations of bond lengths from a model system, usually taken as benzene, but there are variants of this idea in the literature [21][22][23][24]. There are also various measures of aromaticity that more directly involve energetics in one way or another.…”

Aromatic Rules of C22H122+/2•/2–: Flexibility in Electronic Structures of 2D Superatomic Molecules

“…Aromaticity cannot be experimentally directly measured owing to the lack of strict physical definition, but it can be indirectly recognized using various descriptors including structural, , energetic, − reactivity, , and magnetic criteria. − Nevertheless, those indices sometimes contradict each other, such that a set of criteria based on different physicochemical properties are advised . In terms of triangulene, structural and magnetic , criteria identify its aromaticity. Besides, its two charged forms, namely, C 22 H 12 2+/2– , are also aromatic .…”