Abstract
Components of the static electric dipole polarizabilty (α), and second hyperpolarizability (γ); tensors have been determined by accurate ab initio calculations for three molecules containing two conjugated carbon – nitrogen and/or carbon – phosphorus triple bonds. For the NCCP molecule the dipole moment (μ) and non-vanishing components of the first hyperpolarizability (β) tensor have also been calculated. Electron correlation effects have been taken into account by the second-order Many Body Perturbation Theory (MBPT(2)), and coupled cluster (CCSD and CCSD(T)) calculations. The basis set developed by Sadlej (Pol) and designed to be used in electric properties calculations together with its extension (HyPol) have been applied and compared to the results obtained with the standard aug-cc-PVTZ sets of Dunning.