Perturbation theory is a useful systematic mathematical method to obtain an approximate solution to such an equation. It has been one of the most used methods for chemical calculations for over 50 ...

Vertical, well-to-well, and adiabatic ionization energies (IEs) and electron affinities (EAs) were calculated for the n=1-10 [n]acenes using a wide range of semiempirical, Hartree-Fock, density ...