The CN radical was produced using a Penning discharge from a mix of acetonitrile and helium gases.
Researchers measured the ro-vibrational spectra of the CN radical from 16,850 to 17,480 cm(-1) and identified 138 lines for the (6, 1) band and 118 lines for the (7, 2) band in the red system.
They improved the molecular constants and perturbation parameters using a fitting method with high accuracy, as indicated by a standard deviation of less than 0.007 cm(-1).