Potential energy function and vibrational states of N2CO+

Abstract

Articles you may be interested in MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO+(H2O) cluster using accurate potential energy and dipole moment surfaces Theoretical studies of the CO2-N2O van der Waals complex: Ab initio potential energy surface, intermolecular vibrations, and rotational transition frequencies A new four-dimensional ab initio potential energy surface for N2O-He and vibrational band origin shifts for the N2O-He N clusters with N = 1-40 A theoretical and experimental study of the SO 2 2+ dication J. Chem. Phys. 120, 6449 (2004); 10.1063/1.1652544 Unimolecular decay pathways of state-selected CO 2 + in the internal energy range of 5.2-6.2 eV: An experimental and theoretical study A six-dimensional potential energy function ͑PEF͒ for the electronic ground state of N 2 CO ϩ (X 2 AЈ) has been generated by electronic structure calculations using the restricted open shell coupled cluster RCCSD͑T͒ approach. The ion has a planar trans equilibrium structure with: R NN ϭ1.106 Å, R NC ϭ1.905 Å, R CO ϭ1.127Å, NNC ϭ175.3°, and NCO ϭ129.1°. Variational calculations of the vibrational states (Jϭ0) have yielded the following anharmonic wavenumbers for the fundamentals: 1 ͑NN stretch͒ 2287.2, 2 ͑CO stretch͒ 2071.0, 3 ͑CN stretchϩNCO bend͒ 546.9, 4 ͑CN stretchϩNCO bend͒ 215.2, 5 ͑in-plane NNC bend͒ 123.4, 6 ͑out-of-plane NNC bend͒ 133.8 ͑all values are in cm Ϫ1 ). For fixed equilibrium coordinates except one, the barriers to linearity have been calculated to be 8 cm Ϫ1 for the NNC and 2260 cm Ϫ1 for the NCO moieties, the torsional barrier to be 35 cm Ϫ1 . It has been found that the 3 and 4 modes are strongly coupled, the in-plane 5 and out-of-plane 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 ⌸ and the 2 ⌺ ϩ states have been located.

Ab Initio Calculations on the Tricarbon Monoxide Molecule C3O

“…These values agree within 0.01Å with those deduced from experiment (2) and those calculated previously (10,13,14). Such accuracy is expected for similar studies in tetratomic molecules (20)(21)(22)(23) at this level of theory.…”

Accurate Rovibrational Spectroscopic Properties of Cyanogen and Its Isotopomers

“…Nevertheless, the discrepancies between our values and those of this author are only 0.003 and 0.005Å for R CN and R CC , respectively. Such accuracy is expected for similar studies in tetratomic molecules (28)(29)(30) at this level of theory.…”

The potential energy surface and vibrational structure of C3H−

“…The equilibrium distances determined in the present study are expected to be accurate to within 0.01 Å, based on previous work for tetraatomic systems. 15,16 The table also contains the equilibrium structures of both isomers obtained in previous calculations at the CASSCF, QCISD͑T͒, and CCSD͑T͒ levels of theory, 7,8 along with the result of a Hartree-Fock ͑HF͒ calculation employing the cc-pVTZ basis set. 12 The latter calculation was performed to obtain estimates for the infrared ͑IR͒ intensities of the vibrational bands.…”