Ab Initio Modeling of the IR Spectra of Dicyanoacetylene in the Region 100-4800 cm(-1).

Abstract

On the grounds of a hybrid CCSD(T)/B3LYP/aug-cc-pVTZ anharmonic potential and the use of a variational-perturbational method, the IR spectrum of dicyanoacetylene is revisited in the region 100-4800 cm(-1), comparing our results with previous experimental data. A position and intensity analysis of our theoretical results allows us to assign fundamentals, combinations, and overtone bands in the aforementioned range of frequencies. Moreover, the outcomes show a good agreement with the most reliable experimental values and predict several unobserved or unassigned overtones and combinations in the mid-infrared region.