Portion of the CD₃OD THz spectrum dominated by m = 1 K = −12 ← −11 Q-branch and J = 28 ← 27 R-branch transitions in the 1.029–1.030 THz range. The observed spectrum is shown in the lower panel and the calculated one in the upper one. The J quantum numbers for the m = 1 K = −12 ← −11 Q-branch and the K and m quantum numbers (K^m) for the J = 28 ← 27 R-branch are given at the top. It is seen that the experimental frequencies and the intensity pattern are rather well reproduced by our model for the spectral features dominating this frequency range.