Bond distance and vibrational spectrum of the molecular cation NO +2

Abstract

The equilibrium bond distance, vibrational frequencies, infrared intensities, and potential force constants (through quartic force constants) have been determined for the molecular cation NO + 2. Very large atomic natural orbital (ANO) one-particle basis sets have been used in conjunction with the singles and doubles coupled-cluster (CCSD) and CCSD(T) electron correlation methods in this study. The ANO basis sets include up through g-type functions. At the highest level of theory the equilibrium N bond distance is computed to be 1.122 Å, and the uncertainty in this value is conservatively estimated to be ±0.003 Å. The fundamental vibrational frequencies are predicted to occur at 1384, 625 and 2344 cm −1 for μ 1(σ g), μ 2 (π u) and μ 3(σ u), respectively.