Broadband rotational spectroscopy of acrylonitrile: Vibrational energies from perturbations

► Broadband coverage of the rotational spectrum of acrylonitrile up to 1.9 THz and totaling 1170 GHz. ► Analysis of the four lowest vibrational states by means of a coupled fit. ► Precise vibrational energies derived entirely from perturbations in rotational transitions. ► Description of techniques built into the AABS package for efficient treatment of interstate perturbations.