Theoretical studies of nonlinear optical crystals in metal cluster compounds

Theoretical studies and simulations have been applied to explore novel nonlinear optical crystals in metal clusters. The structure-nonlinear optical property relationships of a series of metal cluster molecules have been investigated theoretically within the density functional theory framework. For example, the polarizability and hyperpolarizability of a set of three-nuclear metal cluster compounds of the Mo(W)/Cu(Ag, An) sulfur system are calculated to elucidate the influence of the geometric configuration and the element substitution effect; a set of potential second harmonic generation (SHG) metal cluster crystals are studied and simulated such as the MoAg(2)S5(Py)(PPh3)(2), MoS4Cu4I2(Py)(6) clusters. The results indicate that many of these crystals are promising SHG crystals that may be applied in the infrared (IR) spectroscopic region. The studies are useful to aid in screening, simulating and designing novel nonlinear optical crystals in metal cluster compounds, especially those to be applied in medium/far-IR region. (C) 2002 Elsevier Science B.V. All rights reserved.