CALCULATION OF MACROSCOPIC FIRST-ORDER AND 3RD-ORDER OPTICAL SUSCEPTIBILITIES FOR THE BENZENE CRYSTAL

Starting from a set of high-level ab initio frequency-dependent molecu lar first- and third-order polarizabilities, the macroscopic first-ord er (linear) and third-order (cubic) susceptibilities of the benzene cr ystal are calculated. Environmental effects are taken into account usi ng a rigorous local-field theory and are compared with the anisotropic Lorentz field factor approach. The experimentally determined first-or der susceptibility of crystalline benzene is accurately reproduced. Di spersion curves for the first-order susceptibility and results for ele ctric-field-induced second-harmonic generation and third-harmonic gene ration experiments are predicted. Comparison with similar calculations conducted in the course of molecular simulations of liquid benzene sh ows that the theoretical results for the two phases are of comparable accuracy. Overall, the results show that for the fairly compact nonpol ar benzene molecules, environmental effects on the effective molecular response are small.