ABSTRACT:The linear dipole polarizability α and nonlinear second dipole hyperpolarizability γ of benzene were calculated using the ab initio SCF-MO restricted Hartree-Fock (HF) method. The coupled perturbed HF and time-dependent HF (TDHF) methods were used for the evaluation of the static and dynamic properties, respectively. The TDHF approach was applied at different optical frequencies, and the second hyperpolarizability γ was evaluated for different optical processes. Electron correlation was taken into account by using the Møller-Plesset perturbation theory (MP2) and the density functional theory B3LYP hybrid approach, with a finite field method, with electric fields of ±0.01, ±0.02, ±0.03, and ±0.04 a.u. used. Benzene was assumed to have a D 6 h geometry, and the standard STO/6-31+G(d, p) (A) and optimized STO/6-31+G(d * , p) (B) basis sets were employed for the calculations. In the optimized basis set, the d exponent of the C atomic function was varied in order to obtain a maximum static benzene γ at the TDHF level of theory. This optimized basis set was able to gives values for the