Structure and stability of (CuNO)(+) isomers

Quantum-mechanical calculations have been performed on various isomers of the (CuNO)(+) system. A (2) Pi ground state is found for the linear CuNO+ and CuON+ isomers and a (2)A' State for the bent CuNO+ and CuON+ isomers. Energy calculations indicate that the linear CuNO+ structure is the most stable, the bent CuNO+ and CuON+ and the linear CuON+ structures are at 0.86 eV, 0.99 eV and 1.04 eV above this respectively. In the CuNO+ --> CuON+ interconversion between the linear isomers, three transition states are involved, whereas the bent CuNO+ isomer is found to be an intermediate species. The isomerization barriers, dissociation energies, equilibrium geometries and vibration frequencies are given for all isomers in their ground and first excited states.