Affiliations: [a] Laboratory of Computational Sciences, Department of Computer Science and Technology, University of Peloponnese, Tripolis, GR-22 100, Greece | [b] Division of Theoretical Chemistry, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, A-6020, Innsbruck, Austria | [c] Department of Chemistry, University of Patras, GR-26 500, Patras, Greece | [x] Department of Chemistry, University of Patras, Greece | [y] Departamento de Quimica, CINVESTAV, Centro De Investigacion Y De Estudios Avanzados, Av. Instituto Politecnico Nacional, 2508, A.P. 14-740, Mexico, D.F. 07000, Mexico
Abstract: We have calculated the static polarizability and second hyperpolarizability of sodium tetramer using conventional ab initio and density functional theory based methods. Our best values for the mean and the anisotropy of the dipole polarizability are α¯=548.81 and Δα=489.14 e2a02Eh−1. The mean second hyperpolarizability is very large at γ¯=5531×103 e4a04Eh−3. The differential-per-atom polarizability is negative but the differential-per-atom hyperpolarizability is positive. Density functional theory methods offer a rather fuzzy picture of the second hyperpolarizability of the molecule. Nevertheless, we have found that the widely used B3LYP and B3PW91 methods perform rather reliably for both the polarizability and the hyperpolarizability of Na4.
