Ab initio study of the interaction hyperpolarizabilities of HCN-HF and HNC-HF complexes

The effects of the intermolecular interaction on dipole moment (mu), the mean (alpha) and anisotropy (Deltaalpha) of the polarizability, and the first and second hyperpolarizabilities (beta and gamma, respectively) of HCN-HF and HNC-HF complexes have been calculated in finite-field approach. The augmented correlation-consistent basis sets x-aug-cc-pVXZ (x = s, d, t; X = D, T, Q) are employed to study the effects of the basis sets. Using the d-aug-cc-pVTZ basis set, we calculated the electric properties at the coupled-cluster theory with single and double substitutions and perturbatively linked triple excitations, CCSD(T) level. The electron correlation effects for those electric properties are discussed. The value of each electric property calculated for HCN-HF is less than that for HNC-HF. The mu = 2.2918 au, alpha = 23.186 au, Deltaalpha = 14.393 au, beta = -6.03 au, and gamma = 2553.4 au for HCN-HF; mu = 2.3338 au, alpha = 24.383 au, Deltaalpha = 14.875 au, beta = 7.60 au, and gamma = 3049.3 au for HNC-HF. The electric properties coming from the interaction parts are as follows: mu(int) = 0.3908 au (17.1%), alpha(int) = 0.181 au (0.8%), Deltaalpha(int) = 4.300 au (29.9%), beta(int) = 6.02 au (-99.8%), and gamma(int) = -492.0 au (-19.3%) for HCN-HF; mu(int) = 0.4080 au (17.5%), alpha(int) = -0-084 au (0.3%), Deltaalpha(int) = 5.041 au (33.9%), beta(int) = -7.20 au (-94.7%), and gamma(int) = -931.7 au(-30.6%) for HNC-HF. The estimated electron correlation corrections are beta(corr) = 6.59 au and gamma(corr) = 549.2 au for HCN-HF and beta(corr) = -9.49 au and gamma(corr) = 1056.5 au for HNC-HF.