The CH3D absorption spectrum between 5000 and 6200 cm-1: Empirical line list and rovibrational assignments based on variational calculations

The absorption spectrum of monodeuterated methane, CH3D, is studied in the 5000-6200 cm-1 region by high resolution Fourier transform spectroscopy at room temperature. An empirical list including 27,600 lines was retrieved from two spectra. Relying on the position and intensity agreements with a new variational line list, about 10,150 transitions are rovibrationally assigned to 43 bands, 24 of them being newly reported. Variational positions deviate from measurements by up to 1.5 cm-1 and the variational band intensities are found in agreement with measurements within typically 10 %. Most of the reported assignments are confirmed by Lower State Combination Difference (LSCD) relations i.e. their upper state energies (4039 in total) have coinciding determinations through several transitions (up to 8). The energy values are determined with a typical uncertainty better than 2 x 10-3 cm-1. The intensity sum of the transitions assigned in the region represents 80.4 % of the total experimental intensities in the region.