Precise pariser‐parr‐pople molecular orbital calculations using new‐γ. A novel guiding principle for the design of functional materials

For precise Pariser‐Parr‐Pople molecular orbital (PPP MO) calculations, the values of the spectrochemical softness parameter k of a new two‐center electron repulsion integral new‐γ were evaluated based on an appropriate partial structure of polycyclic aromatic hydrocarbons (PAHs). The spectroactive aromatic sextet resonance system (ASRS) was defined as a spectroactive partial structure of a molecule. The calculated excitation energies of the p ‐band of PAHs accurately reproduced the observed ones.