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Journal Articles Journal of Chemical Physics Year : 1999

Potential energy function and vibrational states of N2CO+

Céline Léonard
E. E. Ferguson
  • Function : Author
P. Rosmus
  • Function : Author
E. A. Reinsch
  • Function : Author
S. Carter
  • Function : Author
N. C. Handy
  • Function : Author


A six-dimensional potential energy function (PEF) for the electronic ground state of N2CO+ (X (2)A(')) has been generated by electronic structure calculations using the restricted open shell coupled cluster RCCSD(T) approach. The ion has a planar trans equilibrium structure with: R-NN=1.106 Angstrom, R-NC=1.905 Angstrom, R-CO=1.127 Angstrom, theta(NNC)=175.3 degrees, and theta(NCO)=129.1 degrees. Variational calculations of the vibrational states (J=0) have yielded the following anharmonic wavenumbers for the fundamentals: nu(1) (NN stretch) 2287.2, nu(2) (CO stretch) 2071.0, nu(3) (CN stretch+NCO bend) 546.9, nu(4) (CN stretch+NCO bend) 215.2, nu(5) (in-plane NNC bend) 123.4, nu(6) (out-of-plane NNC bend) 133.8 (all values are in cm(-1)). For fixed equilibrium coordinates except one, the barriers to linearity have been calculated to be 8 cm(-1) for the NNC and 2260 cm(-1) for the NCO moieties, the torsional barrier to be 35 cm(-1). It has been found that the nu(3) and nu(4) modes are strongly coupled, the in-plane nu(5) and out-of-plane nu(6) bending modes possess an inverse anharmonicity and fall into clusters. Using complete active space self-consitent-field CASSCF approach on the collinear cuts of the PEF for low-lying excited states several conical intersections between the (2)Pi and the (2)Sigma(+) states have been located. (C) 1999 American Institute of Physics. [S0021- 9606(99)30135-5].
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Dates and versions

hal-00693857 , version 1 (03-05-2012)



M. Hochlaf, Céline Léonard, E. E. Ferguson, P. Rosmus, E. A. Reinsch, et al.. Potential energy function and vibrational states of N2CO+. Journal of Chemical Physics, 1999, 111 (11), pp.4948--4955. ⟨10.1063/1.479754⟩. ⟨hal-00693857⟩
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