Absorption Spectrum of Pure H₂S in the 6227.506–6236.844 and 6244.188–6245.348 cm⁻¹ Ranges: Absorption Line Positions and Intensities, Self-Broadening and Self-Shift Coefficients

The absorption spectrum of the H₂S molecule is recorded with high spectral resolution (0.00016 cm⁻¹) and threshold sensitivity (∼1E-26 cm/molec.) in the 6227.506–6236.844 and 6244.188–6245.348 cm⁻¹ spectral ranges at room temperature and pressures of 0.001–0.06 atm for the first time. The measurements were performed at the General Physics Institute, Russian Academy of Sciences, at a high-sensitivity high-resolution diode laser spectrometer with a signal-to-noise ratio of more than 10 000. Line center shift coefficients Δ₀/P and collisional widths Γ₂/P are estimated for the first time; new spectral lines have been recorded. The experimentally estimated line centers differ from the calculated positions of line centers in the HITRAN database by Δν = (ν_H − ν_exp) × 10³ cm⁻¹ ≈ 0.001–0.01 cm⁻¹. The intensity estimates coincide much worse, the relative differences 100% × (S_H − S_exp)/S_H amount to tens of percent; the intensities of five lines differ by hundreds of percent or more.