QUANTUM COMPUTATIONAL STUDIES ON PORPHYCENE - Theoretical and Computational Research in the 21st Century - page 171

For porphycene, the determinant is

where x = (α − E )/β
By solving these determinants, eigen values are obtained for the mo-
lecular orbitals in terms of α and β. The calculated α's and β's for the mol-
ecules are given as follows:

Molecule α (au) β (au)

Pyrrol −0.178601 −0.227117

Porphycene 1.056 2.67686

The density functional global reactivity parameters μ, χ, η, S , and ω for
the above-mentioned four molecules are calculated using the Eqs. (1), (7),
(8), (4), and (13), respectively.