The experimental data were taken from
(1) R. L. Kuczkowski, F. J. Lovas, R. D. Suenram, R. P. Lattimer, K. W. Hillig II, and A. J. Ashe III, 1981, J. Mol. Struct. 72, 143.
Several higher order distortion parameters were evaluated from 3-butynenitrile. The calculations were truncated at J = 60 and 275 GHz and are sufficient for searches in dark clouds. Transitions with calculated uncertainies exceeding 0.2 MHz should be viewed with caution. Spin-statistics were considered in the calculation.
The dipole moment was determined in (1).