1：Experimental Design and Method Selection:

The study used Fourier transform infrared spectroscopy with a Bruker IFS125HR spectrometer to record high-resolution spectra. The analysis involved assigning transitions, determining upper ro-vibrational energies, and fitting parameters using the Watson Hamiltonian and effective dipole moment operator. Isotopic substitution theory was applied for parameter estimation.

2：Sample Selection and Data Sources:

Spectra were recorded from deuterated hydrogen sulfide samples produced by deuterium-hydrogen exchange in optical cells. The samples contained HD32S and HD34S isotopologues due to natural abundance and exchange processes.

3：List of Experimental Equipment and Materials:

Bruker IFS125HR Fourier transform infrared spectrometer (Zurich prototype ZP2001), stainless steel optical multiple-path cells with path lengths of 4 m and 163 m, detectors (MCT), beam splitters (KBr), windows (CsI and KBr), and calibration gases (CO2, N2O).

4：Experimental Procedures and Operational Workflow:

Spectra were recorded at resolutions of 0.002 and 0.003 cm?1 over 28 and 33 hours. Transitions were assigned using ground state combination differences. Line positions and intensities were analyzed, and parameters were fitted using weighted procedures.

5：002 and 003 cm?1 over 28 and 33 hours. Transitions were assigned using ground state combination differences. Line positions and intensities were analyzed, and parameters were fitted using weighted procedures. Data Analysis Methods:

5. Data Analysis Methods: Data were analyzed using the Watson Hamiltonian for energy levels and the Hartmann-Tran profile for line intensities. Statistical methods included root mean square deviations and weighted fits.