ABSTRACT
The nonlinear optical properties of the 2-methyl-4-nitroaniline (MNA) and of the 3-methyl-4-nitropyridine-1-oxyde (POM) crystals are determined using the supermolecule approach within ab initio and semi-empirical quantum chemistry techniques. The static and dynamic (SHG) second-order susceptibilities are evaluated from the knowledge of the first hyperpolarizability of the constituting onedimensional molecular clusters by using a simple multiplicative scheme.
