Knowledge Bank

The harmonically coupled, anharmonic oscillator model, developed by Child and co-workers, has been extremely successful in describing the stretching vibrational levels of symmetric hydrides, such as acetylene. I have made corresponding approximations to develop an effective. Hamiltonian to describe the bending modes of acetylene, including the interactions between the modes. As in the stretching case, the resulting Hamiltonian is equivalent to a traditional treatment, but with a set of $x-K$ relations between the anharmonic and interaction constants. In the present case, however, these relations do not even approximately reproduce the experimentally determined constants. Reasons for the failure of the model will be discussed.