Infrared Transitions of H12C14N and H12C15N between 500 and 10 000 cm-1.

We have measured the Fourier transform spectrum (FTS) of two isotopomers of hydrogen cyanide (H12C14N and H12C15N) from 500 to 10 000 cm-1. The infrared data have been combined with earlier published microwave and submillimeter-wave measurements. From this analysis new vibration-rotation energy levels and constants are given, based on the observation of a number of new vibrational levels, especially for H12C15N. The Coriolis interaction involving Deltav3 = -1, Deltav2 = 3, and Deltal = ±1 has been observed for a great many levels and in some cases the assignments of laser transitions allowed by this interaction are more clearly shown. New vibration-rotation constants are given that allow one to predict the transition wavenumbers for most of the transitions below 10 000 cm-1 with accuracies of about 0.5 cm-1 or better. Values are given for the power series expansion of the l-type resonance constants and for the centrifugal distortion constants, as well as the usual vibrational and rotational constants.