ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Stretching potential energy and dipole moment functions have been calculated for the ground electronic states of the HNC+ (X 2Σ+) and HCN+ (X 2Π) radical ions by singles and doubles configuration interaction (CI-SD) with a basis set of 74 contracted Gaussian-type orbitals. By comparison to analogous calculations on the CN radical, the ground state rotational constants B0 of HNC+ and HCN+ are predicted to be 47, 122±70 MHz and 40, 185±70 MHz, respectively, by CI-SD with the addition of a size consistency correction, designated CI-SD(s). Stretching band origins and intensities have been obtained from the analytical potential energy and dipole moment functions using variational methods. The stretching fundamental band origins, ν1 and ν3, and their intensities are predicted to be 3464 cm−1/2507 cm−2 atm−1 and 2212 cm−1/2.3 cm−2 atm−1, respectively, for HNC+ and 3099 cm−1/1189 cm−2 atm−1 and 1806 cm−1/70.3 cm−2 atm−1 for HCN+. The equilibrium dipole moment of HNC+ calculated by CI-SD is just 0.66 D, while that of HCN+ is 3.63 D. In agreement with earlier studies the HNC+ isomer is predicted to be lower in energy than HCN+, and our calculated energy of isomerization, 18.91 kcal/mol, is in good agreement with this previous work. The Renner–Teller effect in the HCN+ isomer is predicted within the harmonic approximation by CI-SD(s) to be small, with the Renner parameter ε and the Renner–Teller constant εω2 being −0.056 and −39.2 cm−1, respectively (ω2=696 cm−1). Quadrupole coupling constants have also been computed for HNC+ and HCN+, as well as for the neutrals HCN and HNC. The proton affinity at zero temperature PA0 of CN is 150.6 kcal/mol by CI-SD(s), and the adiabatic ionization potentials of HNC and HCN are 273.3 and 307.7 kcal/mol.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.458683
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