The Hückel theory is more accurate for alternant hydrocarbons.

There exist long alternant codes which meet the Gilbert-Varshamov bound.

Alternant hydrocarbons display three very interesting properties:

The method is particularly efficient for alternant hydrocarbons in which the coefficients of the non-bonding orbitals involved are very easy to calculate.

It is a structural isomer of the alternant PAH pyrene.

The name Wia is an alternant spelling of the Wea tribe's name.

An alternant hydrocarbon is any conjugated hydrocarbon system which does not possess an odd-membered ring.

In linear algebra, an alternant matrix, is a matrix with a particular structure, in which successive columns have a particular function applied to their entries.

An alternant determinant is the determinant of an alternant matrix.

The parameters of this alternant code are length n, dimension n mδ and minimum distance δ + 1.

Moreover, if the alternant hydrocarbon contains an odd number of atoms then there must be an unpaired orbital with zero bonding energy (a non-bonding orbital).

Alternant matrices are used in coding theory in the construction of alternant codes.

PAHs composed only of six-membered rings are called alternant PAHs.

Examples of alternant matrices include Vandermonde matrices, for which and Moore matrices for which .

In coding theory, alternant codes form a class of parameterised error-correcting codes which generalise the BCH codes.

Certain alternant PAHs are called "'benzenoid"' PAHs.

Molecules with MO's paired up such that only the sign differs (for example α β) are called alternant hydrocarbons and have in common small molecular dipole moments.

The set of alternant PAHs is closely related to a set of mathematical entities called polyhexes, which are planar figures composed by conjoining regular hexagons of identical size.

Its presence is an indicator of less efficient or lower-temperature combustion, since non-alternant PAHs are less preferred in formation than alternant PAHs.

If and the functions are all polynomials we have some additional results: if for any then the determinant of any alternant matrix is zero (as a row is then repeated), thus divides the determinant for all .

Note that this form of the parity-check matrix, being composed of a Vandermonde matrix and diagonal matrix , shares the form with check matrices of alternant codes, thus alternant decoders can be used on this form.