Analysis of the ν7+ν9 and 2ν7−ν9 band complexes of dicyanoacetylene (NC-CC-CN)

A recently developed theory of intensities in such band systems has been applied to the ν7+ν9 band. Examples of intensity calculations illustrate some spectacular effects of the rotational and vibrational ℓ-type resonances on intensities. The observed intensities are in good agreement with the predicted values within the expected J-ranges.