The emission spectroscopy of the [formula omitted] system of the CD radical

Abstract

The emission spectrum of the 0-0,1-1 and 2-2 bands of the C2Σ+-X2Π system in the CD molecule have been obtained using a stainless steel hollow-cathode lamp with two anodes and filled with a mixture of He buffer gas and CD4. The emission from the discharge was observed with high accuracy dispersive optical spectroscopy using a plane-grating spectrograph and recorded by a photomultiplier tube. In total, 428 transition frequencies belonging to the three bands were precisely measured and rotationally analyzed. The current data were elaborated with the help of precise ro-vibrational and equilibrium ground state parameters reported by Zachwieja et al. (2012) from investigation of the A2Δ-X2Π transition. The spin-rotation interaction constants γv and γD,v of the C2Σ+,v=0,1,2 levels were obtained for the first time. Moreover, the main equilibrium parameters of the third excited state were obtained as follows: Te=31,825.944(12) cm−1, ωe=2078.803(27) cm−1, ωexe=59.558(12) cm−1, Be=7.86810(23) cm−1, αe=0.25315(58) cm−1 and γe=-0.01518(28) cm−1.