Charge distribution, electric multipole moments, static polarizability and hyperpolarizability of silene

We have obtained electric properties for silene from finite-field, high level ab initio calculations with molecule-specific Gaussian basis sets. Our best values, calculated at the CCSD(T) level, are μz = −0.2613 ea0 for the dipole moment and α ¯ = 47.70, Δα = 18.41 e 2 a 0 2 E h - 1 for the mean and anisotropy of the polarizability. For the first and second hyperpolarizability we report β ¯ = 45.86 e 3 a 0 3 E h - 2 and γ ¯ = 20 682 e 4 a 0 4 E h - 3 . Very important electron correlation effects were found for the first hyperpolarizability. A comparison with the properties of ethene brings forth the empirical relationships α ¯ (H2SiCH2) ≈ 1.7 × α ¯ (H2CCH2) and γ ¯ (H2SiCH2) ≈ 3 × γ ¯ (H2CCH2).