Applying the procedure of precise Pariser-Parr-Pople molecular orbital (PPP MO) calculations, in which a novel two center electron repulsion integral new-y was used and spectrochemical softness parameter in the newy was evaluated based on the spectroactive aromatic sextet resonance system (ASRS) of a molecule, the wavelengths of the p-band of acenes and their higher analogues were predicted. The relationship between the annellation and the shift of the wavelength of the p-band was revealed. The guideline to design PAHs which possess the long absorption wavelengths was proposed.