Representations of molecular force fields. I. Ethane: <i>A</i> <i>b</i> <i>i</i> <i>n</i> <i>i</i> <i>t</i> <i>i</i> <i>o</i> and model, harmonic and anharmonic
The quadratic and selected cubic force constants for ethane have been computed, using single determinant molecular orbital wavefunctions at the 4-31G level, with a view to testi...