Using INDO/CI series methods, the 2nd-order nonlinear optical susceptibilities bijk of substituted benzenes, such as: aniline, nitrobenzene, o-nitroaniline, m-nitroaniline, p-nitroaniline and 2,4-dinitroaniline were studied. The agreement between theory and experiment is quite satisfactory. The bx depends on the quantity and possibility of the intramol. donor-acceptor charge transfer.

Key words: BENZAMINE P, COEFFICIENTS, CALCULATION, QUANTUM CHEMISTRY, NITROBENZENE P, TWO-ORDER, NON LINEAR OPTICS, INTERMEDIATE NEGLECT OF DIFFERENTIAL OVERLAP APPROXIMATION (IND, NON-LINEAR MATERIALS